According to the NHL's hockey operations guidelines, every NHL team must submit an Opening Day Playing Roster consisting of at least 20 players, and no more than 23 players in active status at any time.

The Blue Jackets normally invite 60 skaters and 6 goaltenders to training camp. Of those, 18-19 of the skaters and at least two of the goaltenders played in the NHL the previous season.

Thanks to Scott Howson's aggressive roster upheaval, the Jackets are expected to have a fierce competition for available roster spots among players like Ryan Johansen, Aaron Johnson, David Savard, and John Moore, but it's worth asking just how many spots are really up for grabs.

1) Returning Players

If we assume the Jackets will devote 12 spots to forwards, 7 to defense, and of course the mandatory two goaltenders, the first thing to look at is the players who are either returning "NHL regulars" or offseason acquisitions.

I set the "regulars" mark for any player who appeared in more than 40 games for the club last year, with two exceptions - Grant Clitsome, who would have hit the mark if he hadn't been injured near the end of the season, and Kristian Huselius, who will be starting the season on Long Term Injured Reserve and is not being considered since he won't be able to compete at camp.

Forwards:

Nash, Carter, Prospal, Umberger, Brassard, Vermette, Calvert, Pahlsson, MacKenzie, Dorsett, Boll - 11

Defense:

Tyutin, Wisniewski, Methot, Clitsome, Martinek, Russell - 6

Goaltending

Mason, Dekanich - 2

On paper, anyone hoping to make the club out of camp is already on a pretty steep slope - the team's goaltending tandem was essentially set by default when Scott Howson offered Mark Dekanich a 1 way contract, one spot is open on defense, and one spot on the fourth line is available.

Where things get tricky is on the forward lines - we've discussed earlier this season that the team could potentially choose between Derek Dorsett and Jared Boll for a single spot, depending on how Scott Arniel wishes to play this season, and of course there's the discussion about setting up different line combinations.

Should the coaching staff opt to put Boll or Dorsett in the press box as a healthy scratch, that would potentially open a second spot for a motivated camper, as could a decision to look at Derek MacKenzie as a replacement for Sammy Pahlsson, should he continue to show some speed issues. For now, I'd call it likely that two spots are truly "open", with the third possible, but not likely.

On the defense, I would actually expect the team to assume that a second slot could be available simply based on recent history - for various reasons (injury, illness, conditioning) the club has seen an NHL level d-man go down during training camp for at least the first few weeks of the season. While I hate to pick on Kris Russell (and I firmly disagree with the 'rumors' that he could be available in a trade), he's had some durability issues and the team might hedge their bets about his availability out of camp. The team's offseason acquisition of Radek Martinek also was a move that could provide some veteran stability, but also comes with a potential for the former Islander to miss significant time - he hasn't played 60+ games in a season since 2007-2008.

Saying that there might be opportunities for four players out of the 40+ coming to camp without guaranteed jobs is still slim, but it's still quite an improvement over perhaps two having a shot.

2) Potential Breakouts

Last season, the Jackets had several nice camp surprises, from David Savard showing a strong presence in pre-season action to the emergence of camp invite Oliver Gabriel as a legit prospect and earning an entry level contract from his tryout deal. This season, a camp invitee might earn an entry level, as Gabriel did, but most of the players likely to crack the roster are players already in the system.

Here's a look at the players I think are most likely to push for a spot:

Forwards

Ryan Johansen - an elephant in the room for any discussions of next season's roster, the 2010 4th overall pick has little to learn by returning to the WHL, and is likely to push any and all comers for a chance to make the club this season.

Cameron Atkinson - The former Boston College winger made a solid debut with Springfield at the end of last season and showed some silky smooth hands as he tore through the club's prospect camp this summer.

Maxim Mayorov - After slowly adjusting to the North American game in Syracuse and Springfield, "Max" didn't look out of place when given a brief look late last season in Columbus. There was some concern of him being a flight risk to the KHL, but he arrived in Columbus to take part in former coach Gary Agnew's workout camp with several other Jackets and appears to be committed to making an impact. He's on the final year of his entry level deal, so we could see him push hard as part of trying to earn a new contract.

Tomas Kubalik - Another player who impressed during last season's camp, Kubalik spent the majority of last season in Springfield, where he lead the Falcons in scoring. His name comes up quite often when people discuss the possibility of a third scoring line, where he might make a natural fit with former Springfield linemate Matt Calvert.

Alexandre Giroux - Though Giroux is penciled in to provide scoring and leadership in Springfield, the Jackets had another former Hershey Bear in camp last season named Kyle Wilson who provided quite a surprise. Don't be shocked if Giroux pushes hard and could be one of the last to be cut.

Cody Bass - Though Bass is generally regarded as a checking line player, he's generally been regarded as being "NHL ready". He's a strong candidate to push for one of those fourth line positions.

Defense

Aaron Johnson - "Bubba" is coming in as a former Jacket, with ties to many current roster players (not the least being childhood friend Rick Nash), looking to play his way back to the NHL after spending the season with Milwaukee of the AHL in 2010-2011. Never a huge scoring threat at the NHL level, he put up a respectable 9 G 26A last year. His biggest knock has been his defensive consistency - if he's made strides there, he could show up in that #7 slot.

David Savard - After a solid camp, Savard joined the Falcons for his first full pro season and had 43 points in 72 games in the AHL. Though he spent time in camp as more of a shutdown player, his mobility shows hints of a promising future, especially if he can continue to produce points from the blue line.

Nick Holden - Nick appeared for a few games last season and has been a solid option at the AHL level, but has yet to stand out. Like Mayorov, this is a contract year for him - expect him to push hard.

John Moore - Given a brief taste of the NHL last season, Moore's potential is there, but he needs to continue building up and filling out his 6'3" frame before he can take on playing full time in the NHL. Given his struggles defensively in Springfield last season, I'd expect him to spend more time developing before he really pushes for playing time in Columbus.

Goaltending

Though the goalie tandem is basically set, there's still competition afoot for who will be the starter in Springfield, and who is likely to be on the plane to Columbus should Mason or Deckanich suffer an injury.

Allen York - After spending three seasons with the Engineers at RPI, York appeared in four games for Springfield last season, posting three wins and a shutout. Though he needs more pro experience, I wouldn't be shocked if he has a strong camp and takes the #1 job for the Falcons.

Curtis Sanford - Acquired to mentor York and provide a veteran presence for the Falcons, Sanford is a former NHL netminder but has spent the last three seasons in the AHL - including 16 games with Scott Arniel and the Manitoba Moose. That familiarity with his game and the pro experience over York makes him a bit more likely to get a callup in case of emergency, but I'd expect him to only start 30-40 games and leave the rest to York to let him cut his teeth.

Paul Dainton - Signed by Springfield after graduating from UMass-Amherst, he had a brief stay with the Falcons last season, and is expected to attend the Jackets' camp in hope of earning an NHL deal. Most likely to play in Chicago with the Express, he could play his way into the mix with a strong enough performance.

If you asked me to pick out four guys most likely to make the team, or to be called up early in the season, I would guess Johansen, Johnson, Mayorov, and Savard, but there's still a lot of things that have to happen before anything is decided.