EVERY team has their irreplaceable players. But if injury strikes, and the magnets on the whiteboard need to be shifted around, does your team have a plan B?

Our writers name the three most important cogs in each team's wheel, and how your club would cover their loss - from a straight swap of personnel to some tactical wizardry from the coach.

Rory Sloane: Sloane is one of the Brownlow Medal favourites, so his loss would be keenly felt. It certainly was when North Melbourne's Sam Gibson and Demon Bernie Vince quelled his influence in rounds seven and eight. But not every club has a 307-game midfield bull like Scott Thompson desperate for promotion.

Taylor Walker: The Crows' captain is a beast up forward and an inspirational leader, but they are one club that could afford to be without him for an extended time. The fact Adelaide had the luxury of dropping Josh Jenkins shows the embarrassment of riches it boasts inside 50. Versatile tall Andy Otten has already proven capable of stepping in while Jenkins was out earlier in the year, while Tom Lynch could play closer to goal and Eddie Betts is always happy to accept more passes.

Sam Jacobs: The ruck is rarely a concern for Don Pyke's men when the big 'Sauce' is in the line-up. And that's more often than not, with Jacobs playing at least 19 games in his six full seasons at the Crows. But if the ex-Blue was to suffer an injury, there would have to be a decision made. Does Andy Otten or Kyle Hartigan become the top option in Jacobs' absence, or do they turn to two-gamer Reilly O'Brien, who has impressed in the SANFL? - Marc McGowan

Harris Andrews: It's just his third season, but the young Queenslander has made the full-back spot his own. Jack Frost appears an obvious choice to replace him, but putting the ultimate defensive responsibility on the shoulders of young swingman Dan McStay might be a better option long-term.

Dayne Beams: The skipper has already missed two matches with a quad problem, and is a difficult man to cover with his mix of inside and outside football. Rhys Mathieson could make the step from NEAFL if Chris Fagan wanted a contested ball winner. The Lions could also insert Daniel Rich to a more central role and cover his half-back position with Tom Cutler.

Stefan Martin: The Lions are thin in the ruck, but in Archie Smith they have a good backup if Martin has to miss matches. Smith played three games in 2016, and while his work around the ground is improving, he is excellent around stoppages and could comfortably hold his own as the main man. - Michael Whiting

Archie Smith is a handy backup for star ruckman Stefan Martin. Picture: AFL Photos

Sam Docherty: The ex-Lion is in All Australian form and marshals a well-organised defence. With Sam Rowe gone for the season, Docherty’s presence is vital and the Blues would be forced into a restructure if they lost him. When Irishman Ciaran Byrne returns from a long-term knee injury, he could provide some of the daring run that Docherty provides and maybe Lachie Plowman could step up to be the ‘quarterback’.

Matthew Kreuzer: The ruckman has been in the most consistent vein of form in his career, providing plenty of grunt and linking up well in the midfield. Andrew Phillips, who is on the comeback trail from a foot injury sustained during the pre-season, looms as the logical replacement if the former No.1 draft pick went down, but the Blues would miss the big man dearly.

Marc Murphy: The skipper has been in scintillating touch this season and you only have to go back to last season to see how the Blues coped without him – not very well. Covering him would take a big effort from the midfield, with more responsibility loaded on to the broad shoulders of Patrick Cripps, Bryce Gibbs and Ed Curnow, with help from some of the club’s talented youngsters. - Howard Kotton

Jamie Elliott: The little dynamo hadn't played since 2015 but for the past five weeks he has been the most likely Magpie in attack. Elliott leads the Pies' goalkicking with an efficient 13.5 – the next best in this period has been Darcy Moore's 7.5 – and creates opportunities with his speed, work ethic, marking ability and defensive actions. Without him, the Pies would need greater contributions from the likes of Alex Fasolo and Jordan De Goey, and midfielders such as Scott Pendlebury and Steele Sidebottom could spend more time in the front half. Another high-flyer in Jeremy Howe could also be thrown forward.

Brodie Grundy: The durable, ultra-competitive young ruckman hasn't missed a game since being overlooked for last year's season opener, and has since averaged 18 possessions (plenty for a ruckman), four clearances and 30 hit-outs. In the event of Grundy being sidelined, which would leave a huge hole in the Pies' line-up, raw forward/ruckman Mason Cox would need to shoulder most of the responsibility with support from the likes of young forward Darcy Moore and perhaps even Lachie Keeffe.

Jeremy Howe: The former Demon's importance has only heightened since Ben Reid's latest soft-tissue injury, and his anticipation, contested marking, composure and kicking skills on either side would be difficult to replace. However young, injury-prone defender Matt Scharenberg has found a rich vein of form in the VFL and could be called upon to fill the void. Tom Langdon, also returning from injury, has shown in the past that he's a more than capable intercept player. Or maybe Tyson Goldsack could be released to play a more offensive role. - Ben Collins

Ex-Demon Jeremy Howe has been a standout for the Pies in defence. Picture: AFL Photos

Michael Hurley: The Bombers would be in strife if they lost Hurley, but they could at least move gun swingman Cale Hooker from his forward post to hold down the defence with confidence. Injured duo Patrick Ambrose and Mitch Brown will also be back in the next few weeks which provides the club with some defensive depth.

Joe Daniher: The Essendon spearhead is probably the club's most irreplaceable player. In the case he was unavailable the Bombers would probably play with just two key forwards – James Stewart and Cale Hooker. But they could also change around their structure and bring in ruckmen Tom Bellchambers (six goals in the VFL last weekend) and Shaun McKernan, who have both proved they can take a grab near goal.

Zach Merrett: In this case the Bombers' first move would probably be to shift Darcy Parish into a more prominent midfield role. As for Merrett's possible replacements from outside the Essendon senior side, youngster Kobe Mutch is an accumulating midfielder who would do the same at the next level, while David Myers and Andy McGrath could also spend some more time up the ground. Kyle Langford and Craig Bird are other midfield options out of the side currently. - Callum Twomey

Nat Fyfe: Fremantle's band of inside midfielders are as good as any in the competition but, as we saw last season, losing their main man would be a hammer blow. Fyfe not only attracts the opposition's attention, he stands up in big moments where the contest is fiercest. If he went down again, Ross Lyon's ability to use onballers David Mundy and Lachie Neale up forward – a tactic that has reaped rewards this year - would be severely compromised.

Aaron Sandilands: There is no more important player to the Dockers than the 211cm giant, whose unrivalled tap work kickstarts Freo's engine room. Ruck depth is not a strength for the Dockers either. Jon Griffin doesn't have the same presence, but would be the obvious fall-back option ahead of raw draftee Sean Darcy, and Freo's tactics at centre bounces in particular would have to become more defensive.

Michael Walters: Few players boast Walters' X-factor. The 26-year-old has been spending more time in the midfield but is most valuable in attack – as he proved with a game-turning three-goal third quarter against Carlton – and Freo has no obvious replacement with Hayden Ballantyne sidelined. Hayden Crozier and Brady Grey are competing at ground level, but one of the Hill brothers – Stephen or Bradley – would be needed to offer extra zip up forward if Walters was sidelined. - Travis King

Tom Hawkins: Hawkins is crucial to the Cats' fortunes as their forward-line revolves around the big man who has kicked 27 goals in nine games this season. The Cats could make Harry Taylor their key forward and move Aaron Black into the second tall forward role in his absence or include Rhys Stanley who they fancy as a forward/ruckman. Wylie Buzza has been in good form in the reserves and could get a chance inside 50 this season but he is a developing player.

Tom Lonergan: Although Lonergan is in the twilight of his career he is so reliable that any replacement will be a step down in the short term. Ryan Gardner is the key defender being groomed to take over from Lonergan in the key defensive post however he remains a work in progress. The Cats could switch Taylor back into defence and play Black or Stanley forward.

Patrick Dangerfield: Obviously losing either Dangerfield or Joel Selwood for a long period would put a serious dent in the Cats' premiership chances but a short-term absence would give other midfielders the chance to step up. Steven Motlop has been playing as a forward-mid but it would give him the chance to play as a full-time midfielder, breaking the lines and creating opportunities for key forwards. The other option, of course, would be to pray. - Peter Ryan

Gary Ablett: Almost since their inception, the 'no Ablett, no Suns' saying has rung true, but they finally have some depth to cover if the champion midfielder is missing. Jack Martin would move into a more permanent midfield role, while Jesse Lonergan could be given a prolonged opportunity once overcoming his own injuries.

Tom Lynch: With Sam Day already injured, Lynch is the man the Suns can least afford to lose. Jarrad Grant is the only senior-listed 'tall' forward playing NEAFL that could step in, but surrounding Peter Wright with more mobility could appeal, with Martin a leading forward, and draftee Ben Ainsworth to come back into the team. Switching Steven May forward would be a last resort.

Steven May: Gold Coast has already had a look at this scenario, with May missing two weeks with a hamstring problem. They have precious few options in this part of the ground, but young Jack Leslie is readymade to step into a key defensive post. - Michael Whiting

Young defender Jack Leslie has been used as a fallback option for the Suns. Picture: AFL Photos

Stephen Coniglio: The vice-captain is the man Leon Cameron turns to when he needs someone to run with the opposition's best midfielder, so to have him for just two games this year has been a blow. Coniglio's hardness at stoppage situations makes life extremely tough for his opponent. Ryan Griffen stepped up in his absence before he went down with a long-term ankle injury of his own.

Phil Davis: His fellow co-captain Callan Ward told AFL.com.au earlier this year that Davis was the club's most important player - he's that vital as the anchor of the GWS backline. Davis takes the opposition's best tall forward each week and if they were to lose him, like they have in previous seasons, it places more pressure on teammates Adam Tomlinson and Aidan Corr.

Shane Mumford: The aggressive ruckman has so much presence on the field that he's just about irreplaceable for the Giants. Rory Lobb does a great job giving Mumford a chop-out but isn't quite No.1 ruck ready yet, and that would also rob the forward line of a reliable tall target. The Giants' freefall after Mumford went down in 2015 was no coincidence. - Adam Curley

Tom Mitchell: Nine games into his first season with the Hawks and Mitchell is already emerging as one of the club's most important players because he has been able to address a glaring weakness of the side - winning contested ball. Liam Shiels and Will Langford are OK at the contest, but Hawk fans are looking forward to the debut of rookie-listed midfielder James Cousins, who has been a contested beast in the VFL this year.

Shaun Burgoyne: He's 34, played 92 consecutive games and remains Hawthorn's 'break glass in case of emergency player'. There is nobody like him although Ryan Burton has rarely put a foot wrong since becoming a regular senior player and if he develops he should, like Burgoyne, be able to fit seamlessly anywhere around the ground.

James Frawley: Was probably not playing as well this year as in seasons past, but his absence for the next two months because of a toe injury will really hurt Hawthorn. Plan B is Kaiden Brand, but he didn't play either last weekend because he was ill. Kurt Heatherley was Plan C and he went OK against the Pies, but he still has plenty of development to come. - Ashley Browne

Max Gawn: Melbourne is already onto plans B and C after it lost the star ruckman to a hamstring injury in round three. Losing Gawn had the potential to be a disaster, but at least Jake Spencer was there in reserve. That was until the back-up big man suffered a serious shoulder injury against Richmond in round five. Now, the Demons have been forced to rely on the under-sized Cameron Pedersen, along with Jack Watts and Tom McDonald, to compete in the ruck. The Demons have been smashed in hit-outs (-143) over the past month, but have offset that loss by winning the clearances (+32). However, Gawn's slated return in round 12 cannot come quick enough.

Jesse Hogan: The Demons have only had the power forward available for four games this season and it is unclear when he will be able to return to the field after being diagnosed with testicular cancer. Hogan's interrupted year has forced the Demons to be creative with their forward structure, with second-year forward Sam Weideman and first-year rookie Tim Smith both having opportunities to play as the tall forward alongside Jack Watts. Tom McDonald has also spent time down there as a key target.

Neville Jetta: The small defender has become an integral part of the Demons' line-up, given his ability to play as a lock-down defender on some of the AFL's most damaging small forwards. Jetta has also improved the offensive side of his game immensely, which has made him a more valuable asset. Should Jetta be unavailable for selection at any point this year, especially with Colin Garland gone for the year with a knee injury, the Dees would look to push Tom Bugg back into defence or perhaps look to Jake Melksham to fill that spot. - Ben Guthrie

Former Giant Tom Bugg flies high for a mark. Picture: AFL Photos

Ben Cunnington: There is no-one better in the contest at the Roos than the No.5 pick from the 2009 draft, but he is one player they could cover – although not at the same level – in the short term. Jack Ziebell and Trent Dumont would carry a heavier load and former skipper Andrew Swallow's time in the middle would spike significantly.

Robbie Tarrant: Tarrant is largely irreplaceable at North, given his ability to lock down on the best key forwards, take intercept marks and provide defensive rebound. If the reigning club best and fairest was to go down for a period of time, the one positive is it may give Sam Durdin or even the improving Daniel Nielson the extended run in the senior team they are finding hard to obtain. Another option in this case is for the Roos to go down Carlton's path in always playing an extra defender and generally not venturing too far down the ground as a group as a protective course of action.

Ben Brown: The Tasmanian forward is arguably already North's No.1 player in attack – and certainly its most reliable – with Jarrad Waite getting on in years and still unable to regularly stay on the field. There are key forward prospects for down the track, such as Ben McKay and Nick Larkey, but the only man waiting in the wings with genuine readiness is Majak Daw, who, like Waite, has proven frail and inconsistent. - Marc McGowan

Robbie Gray: Replacing a midfielder/forward of Gray's prowess is nearly impossible. Chad Wingard has already increased his midfield time this season but would likely be thrown in there even a little more if Gray was out, while up forward someone like Karl Amon could feature more prominently. Angus Monfries and Jake Neade are others who could be used in attack if the Power wanted to go that way.

Charlie Dixon: The Power brought in mature-ager Brett Eddy last year knowing he could make an immediate impact, and if Dixon was unavailable, Eddy could provide some handy relief near goal. Eddy has played three games this season for three goals but, at 27, has the physical maturity to step into the senior side with confidence.

Paddy Ryder: Ryder rucks best when he goes solo, which has meant Matthew Lobbe has been out of the side all of this season. But at least the Power have some back-up there if Ryder was unavailable. Peter Ladhams was picked in last year's NAB AFL Rookie Draft but won't be ready just yet to take on a ruck role at senior level. - Callum Twomey

Dustin Martin: Losing the 2016 club champion would be a nightmare for the match committee, which would need to find solutions both in the midfield and forward 50. Martin's absence would likely see Josh Caddy thrown more opportunities in the centre square, where Martin leads the club for centre clearances. Resting Martin forward and bombing the ball long to him when he is one-out has been a key tactic. The Tigers would have to use their speedy small forwards in this isolated role.

Alex Rance: The ability of David Astbury to play on the most dangerous tall forward has freed Rance up in 2017, and his absence would force the Tigers to restructure significantly in defence. Dylan Grimes (193cm) would be forced to play taller and the Tigers would need to replace Rance's rebound (he ranks No.2 at the club with 4.1 rebound 50s a game). An opportunity could be created for Oleg Markov, who played as a rebounding defender in the last eight games of 2016.

Jack Riewoldt: The key forward is arguably the most difficult player to replace in 2017, given the Tigers' lack of depth in this position. With Ben Griffiths (concussion) sidelined, the Tigers would need to play one of Todd Elton and Mabior Chol as a key target and then back their smaller brigade. Sam Lloyd and Ben Lennon would likely receive more opportunities as marking players, while the Tigers' attacking style of play would ramp up even more. Playing patient football would be impossible. - Nathan Schmook

Mabior Chol is a key tall the Tigers could call upon. Picture: AFL Photos

Jake Carlisle: Part of the reason St Kilda's backline has performed relatively well this season is the return of the key defender. Dylan Roberton is playing excellent footy but the inclusions of Carlisle and Nathan Brown have allowed the ex-Docker to focus more on intercepting and rebounding. If Carlisle was forced to miss games, Sam Gilbert could be used to man the opposition's second tall in a makeshift role. That option would give Alan Richardson a slightly more mobile defensive unit.

Nick Riewoldt: The Saints champion's form has tailed off over the last three weeks but his work early in the season was proof enough he remains an important player, whether it be as a focal target in attack or as a link player on a wing who offers brilliant field kicking. Josh Bruce could return to the senior side to offer another forward option while Daniel McKenzie could use his impressive tank on a wing, albeit without the same foot skills as the former captain.

Jack Steven: Having won three of the club's last four club championships is an indication Steven is the best player at the club, but his burst from stoppages also provides a point of difference from Seb Ross, Jack Steele, Koby Stevens and Luke Dunstan. Jade Gresham and Darren Minchington could be used in the midfield more to offer line-breaking pace, while Mav Weller has the aggression and speed to play that role. - Dinny Navaratnam

Lance Franklin: The triple-Coleman medallist is one of the League's best forwards, and his presence doesn't just make the opposition nervous, it helps his teammates enormously. When Franklin is on the field, teams can often assign a couple of players to try keep him under control, but when he's not, the opposition's best defender goes to Sam Reid or Kurt Tippett, and that causes even more problems for the Swans.

Heath Grundy: As the pillar of strength down back, Grundy gives the Swans an ultra-reliable leader who is very rarely beaten one on one, and provides plenty of direction for teammates. His loss would leave the team seriously undersized, and force the likes of Dane Rampe, Aliir Aliir and Harry Marsh to fight well out of their weight division.

Josh Kennedy: Since arriving in Sydney from Hawthorn, the skipper has played 23+ games in each of the last seven seasons, and has proven himself to be the clearance and contested ball king. Kennedy's absence would be felt significantly, but Luke Parker, Dan Hannebery, Isaac Heeney and George Hewett have the capacity to at least share his workload if necessary. - Adam Curley

Harry Marsh may be needed if experienced Swan Heath Grundy went down. Picture: AFL Photos

Josh Kennedy: With Nic Naitanui coming back from a knee reconstruction, there's no disputing Kennedy is the Eagles' most important player and the season could be derailed if the dual Coleman medallist went down. West Coast has options to throw deep forward - headlined by Drew Petrie, Nathan Vardy and Jeremy McGovern - but none could replace the star spearhead.

Jeremy McGovern: The Eagles have plenty of tall backmen, with former club champion Eric Mackenzie and Will Schofield stuck in the WAFL, but McGovern's reading of the play and intercept marking is irreplaceable. Hearts are in mouths every time the 25-year-old comes off the ground sore.

Luke Shuey: Midfield pace is in short supply and losing the reigning club champion would cripple the Eagles' ability to break away from stoppages. Few other Eagles can win contested ball and burst clear of congestion, although Elliot Yeo is one who would most likely be called on for more midfield time if Shuey was out of the side. - Travis King

Marcus Bontempelli: While the Dogs have been able to cover a host of players struck down by injury this season, losing the Bont would deny the premiers their best kick and most influential player. But they do have an eager replacement at the ready, with third-year midfielder Lukas Webb a beautiful kick who is just as competent in contested ball. He just needs more time in the midfield to show his vast improvement.

Tom Boyd: Without recapturing the form that saw him one of the best on Grand Final day, the 21-year-old has been a solid contributor in the ruck in the absence of Jordan Roughead. His versatility gives Luke Beveridge great flexibility, as Boyd is also getting a lot more dangerous up forward. But if he was to succumb to injury, impressive draftee Tim English looks ready to fill the void. In a few VFL games, the 19-year-old West Australian has displayed deft ruck work, contested marking and sound foot skills for a player of 205cm.

Robert Murphy: If the skipper succumbed to another long-term injury, the Dogs would desperately be seeking someone to provide the same dash and dare the veteran playmaker provides in spades. The match committee could do worse than elevate speedster Brad Lynch off the rookie list. While the West Australian is a week away from returning from a hamstring complaint, he's displayed breakaway speed, good decision-making and elite foot skills in his two seasons at Whitten Oval. - Ryan Davidson