 -- It seems like this NFL season more than ever, teams have experienced serious injuries that have weakened their rosters, which means the role of backups is more important than it's ever been. Just in this last week we saw Rob Gronkowski and Tyrann Mathieu, among others, land on injured reserve. And we probably aren't done seeing major injuries hit as the wear and tear of the season takes its toll on players.

The question then becomes: Which team is best suited if one of its starters was to get hurt? To answer that question, we present to you the NFL Depth Chart Rankings, which evaluate the depth of talent on every NFL roster heading down the home stretch of the season and into the playoffs.

First, a few details on how the rankings were constructed. We took the ideal lineup for each team based on their current healthy players, as well as the players likely to return this season, and ranked the backups for each team. These rankings were created using overall PFF Grades of the backup players over their last 1,000 snaps and focused on the strength of the quality backups rather than the inexperienced backups. Each player's grade was capped at plus-5.0 so that an individual backup would not overly influence the team's rating.

The quarterback position was also ignored, since nearly every team would see their Super Bowl dreams shattered if their starting quarterback was hurt. The focus of these rankings is to illustrate how much depth each team features -- and whether they can survive -- in the event starters are lost due to injury.

1. New Orleans Saints

Backups grade: 53.6 | Deepest position group: Halfback

Shallowest: Offensive line | Best non-starter: HB Darren Sproles (+30.2)

The Saints are full of quality offensive skill players, including Sproles, fullback Jed Collins (+16.5) and tight end Benjamin Watson (+15.7), making it so the offense could still be effective if an injury were to occur. On defense, they have serviceable veteran depth at defensive back in Chris Carr (+7.5), Rafael Bush (+4.9) and Isa Abdul-Quddus (+2.1). Due to their heavy rotation of players on both offense and defense, they are prepared for an injury to nearly any of their players.

2. Seattle Seahawks

Backups grade: 40.1 | Deepest position group: Linebacker

Shallowest: Tight end | Best non-starter: LB Malcolm Smith (+15.2)

The Seahawks front seven is filled with part-time players who could be full-time starters on other teams. They are highlighted by Smith, who showed during Bruce Irvin's suspension that he could excel in run defense, pass rushing and coverage, but who now can't get on the field due to how good the starting linebackers are. While there is some depth on offense, there isn't as much compared to other teams.

3. Carolina Panthers

Backups grade: 36.1 | Deepest position group: Running back

Shallowest: Linebacker | Best non-starter: TE Ben Hartsock (+19.4)

When the Panthers want to pound the rock, they have Jonathan Stewart (+14.0) and Mike Tolbert (+25.6) ready to run the ball with Hartsock and Richard Brockel (+7.4) ready to block. The depth at defense isn't nearly as strong, but there are a few decent players such as undrafted rookie Robert Lester (+5.3) and veteran linebacker Dan Connor (+3.0).

4. Minnesota Vikings

Backups grade: 35.4 | Deepest position group: Fullback

Shallowest: Wide receiver | Best non-starter: FB/TE Rhett Ellison (+21.5)

With Adrian Peterson on the roster, it's no surprise the Vikings have acquired depth with run-blockers. Both Jerome Felton (+15.0) and Ellison are among the better run-blocking fullbacks in the league, even though neither has topped 250 snaps this season. Rarely-used third tight end Chase Ford (+2.3) can be an asset run-blocking as well, and backup halfback Toby Gerhart (+5.7) is averaging 7.9 yards per carry this year. Outside of the defensive line, there isn't much proven depth at linebacker or defensive back.

5. Baltimore Ravens

Backups grade: 35.2 | Deepest position group: Inside linebacker

Shallowest: Offensive line | Best non-starter: OLB Pernell McPhee (+32.1)

The Ravens' depth is also mostly in their front seven. At inside linebacker, both Josh Bynes (+2.1) and Arthur Brown (+0.0) play well in their part-time roles with Albert McClellan (+4.4), who played well last year at the bottom of the depth chart. Young defensive lineman Brandon Williams (+3.4) has shown promise as a run-stuffer when the starters need a rest. The offensive line has been a trouble area for the Ravens this season, and part of that is due to the lack of depth.

6. Kansas City Chiefs

Backups grade: 32.4 | Deepest position group: Defensive line

Shallowest: Outside linebacker | Best non-starter: OL Geoff Schwartz (+28.0)

On 47.3 percent of snaps, the Chiefs have run a dime defense, which hasn't left nearly enough playing time for Mike DeVito (+31.2) and Allen Bailey (+2.8), who each typically get the best of the offensive linemen across from them. Throughout the season, the Chiefs have faced injuries on the offensive line, and Schwartz has filled in nicely at either guard position. He hasn't allowed a sack yet this season. As seen recently, there is a big difference between Tamba Hali and Justin Houston compared to the other pass-rushers on the roster.

7. Denver Broncos

Backups grade: 30.4 | Deepest position group: Tight end

Shallowest: Defensive tackle | Best non-starter: TE Jacob Tamme (+16.9)

Last year the duo of Joel Dreessen (+4.0) and Tamme helped count the Broncos' offense among the best in the league, but the offseason addition of Wes Welker and emergence of Julius Thomas have left both players on the bench this season. That depth might be needed depending on how long Welker is out with yet another concussion. Kevin Vickerson landing on injured reserve has really hurt the interior of the Broncos' defense, as first-round rookie Sylvester Williams (-6.8) hasn't made much of an impact in his limited playing time.

8. Tennessee Titans

Backups grade: 28.0 | Deepest position group: Defensive tackle

Shallowest: Halfback | Best non-starter: S George Wilson (+13.2)

The Titans have great depth at some positions, but are lacking in other areas. Wilson, a free-agent addition, has given Tennessee one of the best backup safeties in the league. In Tennessee, there just aren't enough snaps on the defensive line to go around with Karl Klug (+25.9) and Mike Martin (+17.0) both excelling at generating an interior pass rush the past two years. On offense, both Craig Stevens (+1.9) and Taylor Thompson (+7.1) are decent run-blockers at tight end.

9. Arizona Cardinals

Backups grade: 27.6 | Deepest position group: Defensive back

Shallowest: Tight end | Best non-starter: NT Dan Williams (+14.6)

The Cardinals are a team that brought in much of their quality depth in the offseason. Sixth-round rookie Andre Ellington (+9.2) has already made an impact as the team's backup running back, while undrafted rookie wide receiver Jaron Brown (+1.8) has played well in his limited opportunities. Marcus Benard (+5.0) and Javier Arenas (+4.9) were added to the roster, but haven't been needed recently due to the depth. Tight end and offensive line are both still problem areas, preventing the Cardinals from ranking higher on this list.

10. Atlanta Falcons

Backups grade: 27.5 | Deepest position group: Halfback

Shallowest: Linebacker | Best non-starter: HB Jacquizz Rodgers (+14.8)

The Falcons' depth is about quality and not quantity, with that quality focused on the offensive skill players. Year after year, Rodgers and Jason Snelling (+3.2) continue to be two of the best backup receiving backs in the league. On defense, the most notable player is fourth-round rookie defensive end Malliciah Goodman (+2.9), who should see his playing time increase this last month of the season. Part of Atlanta's downfall this season has been the lack of depth at linebacker as well as wide receiver.

11. Philadelphia Eagles

Backups grade: 25.7 | Deepest position group: Tight end

Shallowest: Defensive back | Best non-starter: OLB Brandon Graham (+43.7)

Over the past two years Graham has looked like he could be among the best pass-rushers in the league if given the opportunity. At tight end, Zach Ertz (+5.9) has been taking advantage of his increased playing time, followed by James Casey (+5.4), who has been underutilized. Outside of Graham, when other Philadelphia defenders have been asked to step up, they haven't met the challenge.

12. San Francisco 49ers

Backups grade: 25.0 | Deepest position group: Defensive line

Shallowest: Tight end | Best non-starter: DE Glenn Dorsey (+21.8)

The 49ers are a team known for their depth, led by recent free-agent additions Mario Manningham (+7.0) and Dorsey. However, the 49ers haven't been as elite a team this season as last, and part of that has been due to the lack of depth at wide receiver and tight end. The backups in the front seven include a lot of young, unproven players, while the backup defensive backs are mostly players who didn't pan out elsewhere.

13. San Diego Chargers

Backups grade: 24.6 | Deepest position group: Defensive line

Shallowest: Offensive line | Best non-starter: HB Danny Woodhead (+27.1)

The Chargers have used a nickel defense most often this season, which makes Sean Lissemore (+15.2), Lawrence Guy (+8.5) and Cam Thomas (+2.4) all backups -- with Lissemore standing out the most. Whether you consider Woodhead or Ryan Mathews the starting running back, both have played very well when called on. Ladarius Green (+9.3) also looks like a future star at tight end. The Chargers tried to fix the offensive line in the offseason, but it still has a little ways to go. Due to injuries, they lack players who can come off the bench and provide a pass rush off the edge.

14. Cincinnati Bengals

Backups grade: 24.4 | Deepest position group: Wide receiver

Shallowest: Halfback | Best non-starter: WR Marvin Jones (+9.3)

Jones has yet to see a large increase in snaps at wide receiver, but his play on a smaller sample size has continued to be impressive. At nearly every position the Bengals have some depth, with the exception of running back, where BenJarvus Green-Ellis (-11.7) hasn't been playing nearly as well as potential offensive rookie of the year Giovani Bernard.

15. Pittsburgh Steelers

Backups grade: 23.6 | Deepest position group: Tight end

Shallowest: Offensive line | Best non-starter: TE Matt Spaeth (+15.9)

The Steelers get a big boost in their backup grade thanks to Spaeth, who was recently activated and was the best run-blocking tight end in the league in 2012. Outside of the offensive and defensive lines, most of the Steelers' backups haven't seen much playing time in the past. Felix Jones (+4.7) is the only other non-lineman with more than 700 career snaps. For the past few years, the Steelers' biggest problem has been the O-line, and that is no different with their backups this year.

16. New England Patriots

Backups grade: 23.1 | Deepest position group: Defensive back

Shallowest: Defensive line | Best non-starter: HB Stevan Ridley (+9.4)

The Patriots' roster has a few players who have looked good in previous years. If it wasn't for his fumbling problem, Ridley could help form one of the best running back duos in the league. At defensive back (beyond their top six players) they have third-round rookie Duron Harmon (-0.5), second-year safety Tavon Wilson (+5.7) and cornerback Marquice Cole (+1.1), who have all looked decent with limited playing time. The Patriots would be in bigger trouble if they had another injury in the front seven or offensive line.

17. New York Giants

Backups grade: 22.0 | Deepest position group: Defensive tackle

Shallowest: Halfback | Best non-starter: DT Mike Patterson (+16.7)

Over the past two years, the Giants have added a few veteran players at defensive tackle and spent two draft picks on the position, which has clearly made it the deepest they have. The other positions have players you wouldn't want starting, which has hurt the Giants this year, especially on the offensive line and at running back.

18. Detroit Lions

Backups grade: 21.9 | Deepest position group: Halfback

Shallowest: Wide receiver | Best non-starter: HB Joique Bell (+18.8)

The Lions excel with their depth at a few positions. In 2012, Bell proved he could be a receiving threat out of the backfield, and this season he has shown he can run the ball as well. There are few backup defensive tackles who are as good at stopping the run as C.J. Mosley (+19.1), and it's also hard to ignore the six touchdowns from Joseph Fauria (+3.7). However, for years, the Lions have lacked depth at receiver behind Calvin Johnson, and Detroit could run into problems at linebacker if either Stephen Tulloch or DeAndre Levy were injured.

19. Buffalo Bills

Backups grade: 20.3 | Deepest position group: Edge rusher

Shallowest: Tight end | Best non-starter: DE Jerry Hughes (+6.2)

Over these past few years, it's been difficult to find a backup running back better than Fred Jackson (+6.1). Hughes has come off the bench to help join one of the scariest four-man rushes in the league and Marquise Goodwin's (+2.3) recent play might not keep him a No. 4 wide receiver for long. The Bills have one of the least-experienced group of backups in the league, which makes it harder to gauge just how good these players are.

20. Houston Texans

Backups grade: 20.1 | Deepest position group: Offensive line

Shallowest: Halfback | Best non-starter: OT Ryan Harris (+7.8)

The Texans are a rare team that rotates some of their offensive linemen in and out, in this case because the backup offensive linemen have far outplayed the starters. When the Texans use a formation with a fullback, Greg Jones (+24.3) has been ready to go and has played very well. In the past, defensive end Tim Jamison (+4.2) has played well, but he has only been in for 20 snaps this year. Basically every other group for the Texans isn't terrible, but they could each use an upgrade.

21. Green Bay Packers

Backups grade: 18.9 | Deepest position group: Running back

Shallowest: Outside linebacker | Best non-starter: DE Mike Daniels (+17.8)

There has been little to be excited about on the Packers defense this year, but Daniels has been by far the best run defender and interior pass-rusher on the defensive line. When Eddie Lacy has needed a breather, James Starks (+5.2) has made a few big runs, while John Kuhn (+9.7) is quietly having one of his best seasons. There are too many position groups that have lacked depth this year, including tight end, offensive line, outside linebacker and defensive back.

22. Tampa Bay Buccaneers

Backups grade: 15.9 | Deepest position group: Defensive tackle

Shallowest: Offensive line | Best non-starter: DT Derek Landri (+12.2)

The Buccaneers have two backup defensive tackles in Landri and Gary Gibson (+9.3) who have a big history of success, even though they haven't shown it much this year. At running back, while Brian Leonard might never be a lead back, he remains a good role player. Outside of those players, there aren't many guys you would recognize, with the offensive line sticking out as a noticeable weakness.

23. Oakland Raiders

Backups grade: 14.2 | Deepest position group: Halfback

Shallowest: Defensive tackle | Best non-starter: OT Matt McCants (+6.2)

All of the Raiders' noteworthy depth is on offense. McCants, a 2012 sixth-round pick, has had some opportunities at right tackle and has been great in pass protection during that time. While Denarius Moore has been out, Andre Holmes (+3.3) has come out of nowhere with back-to-back good games. The defense hasn't looked great this year, and an injury in the front seven would only make things more difficult for Oakland.

24. New York Jets

Backups grade: 14.0 | Deepest position group: Defensive line

Shallowest: Defensive back | Best non-starter: DT Kenrick Ellis (+14.2)

The strength of New York's starters this year has been the defensive line, which should make it no surprise that the strength of their backups is there as well. Most teams would be happy to have Ellis in the middle of their base defense, and recently Leger Douzable (+9.4) has helped when a defensive end needs a break. The defensive line has been good enough to get the Jets a few wins this season, and their backup defensive linemen are good enough to put them this high in the rankings.

25. Washington Redskins

Backups grade: 13.9 | Deepest position group: Halfback

Shallowest: Defensive back | Best non-starter: OLB Darryl Tapp (+14.5)

In past years, Tapp has been a great backup pass-rusher for the Eagles, and in Washington he should be ready to play if Ryan Kerrigan or Brian Orakpo were to get hurt. Having Darrel Young (+11.3) at fullback is also helpful for when Washington wants out of two-tight end or three-wide receiver formations. There are a number of experienced backups here, but not many that you would want starting.

26. Dallas Cowboys

Backups grade: 13.2 | Deepest position group: Wide receiver

Shallowest: Defensive end | Best non-starter: WR Dwayne Harris (+4.9)

The duo of Harris and Cole Beasley (+2.7) are at the bottom of the Cowboys' depth chart, but each have been surprisingly effective when they've been needed as an injury replacement. A number of backup spots are filled by 2013 draft picks who have yet to make a large impact. The glaring weakness has been on the defensive line, where the roster consists mostly of free-agent replacements who haven't spent much time with the team.

27. Indianapolis Colts

Backups grade: 10.8 | Deepest position group: Defensive line

Shallowest: Cornerback | Best non-starter: S Corey Lynch (-0.1)

The only points of strength for the Colts are at positions where the backups haven't seen much playing time. On the defensive line, both Josh Chapman (+1.2) and Montori Hughes (+1.5) have shown promise on their limited snaps this season, while Weslye Saunders (+3.1) was a decent run-blocking third tight end last year. The roster is full of experienced backups, but they have proven they are below-average players in the league.

28. Cleveland Browns

Backups grade: 10.1 | Deepest position group: Defensive line

Shallowest: Offensive line | Best non-starter: DE Billy Winn (+3.4)

The Browns have the least experienced group of backups in the league, with Jason Pinkston (-5.1), Willis McGahee (+0.7) and Gary Barnidge (+0.5) as the only players above 1,000 career snaps. This means the Browns have a few players who have failed track records as starters, but also a few players who have shown promise.

29. Jacksonville Jaguars

Backups grade: 8.7 | Deepest position group: Cornerback

Shallowest: Defensive tackle | Best non-starter: CB Will Blackmon (+6.3)

Blackmon was brought in to be a return specialist, but he has impressed as a cornerback when called to play outside or in the slot. Jacksonville has a young team, and any young player that has shown some promise has joined the starting lineup at this point in the season.

30. Miami Dolphins

Backups grade: 7.6 | Deepest position group: Defensive end

Shallowest: Halfback | Best non-starter: DT Paul Soliai (+15.9)

The strength for the Dolphins is clearly on the defensive line as Soliai, Dion Jordan (+2.4) and Derrick Shelby (-0.2) are three of the top four rated backups on the team. A big reason for their lack of depth on offense is so many backups have already been asked to take over starting roles, which deteriorated any depth they had.

31. St. Louis Rams

Backups grade: 7.5 | Deepest position group: Offensive line

Shallowest: Halfback | Best non-starter: DE William Hayes (+13.5)

On the bright side, the Rams have Hayes as a great backup to play in pass-rushing situations who can also stop the run. On offense, the Rams have more proven backups than most other teams. On the other hand, the Rams, more than other teams, have players who once started for them, but then decided to go in another direction, moving those players to the bench.

32. Chicago Bears

Backups grade: 6.0 | Deepest position group: Running back

Shallowest: Offensive line | Best non-starter: HB Michael Bush (+1.0)

You can look at Chicago's drafts from 2010-2012 to see why the Bears rank last in depth. They've had 16 draft picks over those years. And while five have become starters for the Bears, nine are already off the team -- leaving just two backups. Their depth consists mostly of unproven rookies and players who had the opportunity to start with Chicago or elsewhere and failed.