Injuries are no fun in the NFL, but they're certainly a part of the game -- as unfortunate but as common as fumbles and interceptions for your favorite team. Oftentimes, teams' title hopes are made or broken by the amount of serious injuries they sustain or avoid. It is, in many cases as they say, a war of attrition.

Which players can teams least afford to lose due to injury in 2021? Discounting losing a quarterback, considering that's the one position almost always guaranteed to devastate a season, here's our take on all 32 teams' most important non-QBs:

Arizona Cardinals: WR DeAndre Hopkins

Kyler Murray is elusive enough to survive injuries up front. But so much of Kliff Kingsbury's offense is predicated on his QB just chucking it up to Hopkins, who's long been something of a deep- and jump-ball specialist. Dating to his days in Houston, Hopkins has caught at least 100 passes for three straight seasons, proving his worth as a big-play safety valve. Plus, if he goes down, you're banking on A.J. Green and injury-prone rookie Rondale Moore to complement Christian Kirk out wide.

DeAndre Hopkins
TEN • WR • #10
REC YDs1407
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Atlanta Falcons: OT Jake Matthews

Losing Calvin Ridley or Kyle Pitts would be huge, especially if Julio Jones is also shipped out, but Matt Ryan also can't really move at age 36. If Arthur Smith is truly trying to win now, capitalizing on a two-year window dictated by the QB's contract, almost everything hinges on Ryan feeling comfortable. And that won't happen if his longtime blind-side protector is absent.

Baltimore Ravens: OT Ronnie Stanley

The Ravens advanced to the playoffs after losing Stanley to an ankle injury, and Lamar Jackson is better than anyone at making plays on his own. But an extended period without a legitimate left tackle isn't good for any QB. Orlando Brown Jr. isn't walking through that door. Marlon Humphrey would be a reasonable name here as well, though Baltimore's better about unearthing defensive starters.

Buffalo Bills: WR Stefon Diggs

Both Gabriel Davis and Emmanuel Sanders can play, but Diggs is on another level. More importantly, his arrival -- and monster production -- coincided with Josh Allen's emergence as an MVP candidate at QB. You can't tell us Allen wouldn't be affected if his top target, responsible for 127 catches and 1,535 yards, left the field. Tre'Davious White might be a close second here at corner.

Stefon Diggs
HOU • WR • #1
REC YDs1535
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Carolina Panthers: RB Christian McCaffrey

Yes, running backs are more replaceable than most positions. Yes, Derrick Brown and Brian Burns and Jeremy Chinn are probably just as valuable at their respective spots. But this year is about restoring/unlocking Sam Darnold, is it not? That's a lot easier if McCaffrey, a dual-threat dump-off option and playmaker, isn't sidelined again.

Christian McCaffrey
SF • RB • #23
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Cincinnati Bengals: OT Jonah Williams

The WR room is loaded, so it's not like losing Ja'Marr Chase or Tyler Boyd or Tee Higgins would completely ruin their lineup. Joe Burrow, meanwhile, must stay upright after his rookie season was cut short due to injury. Williams may not be an elite left tackle, but he's the guy protecting the QB's blind side, and you don't want to be shuffling Riley Reiff and rookies all over the place.

Cleveland Browns: DE Myles Garrett

Would Baker Mayfield be in trouble if Jedrick Wills or Jack Conklin or, frankly, any member of the Browns' O-line went down? Perhaps. But Kevin Stefanski is smart enough -- and Cleveland's roster is balanced enough -- to work around that. Garrett is simply the most dominant player in the lineup, and the drop off from him to Takk McKinley and even Jadeveon Clowney is steep.

Chicago Bears: WR Allen Robinson

The O-line is a question mark regardless of whether anyone gets hurt. Ditto for the secondary. The only way they're making any noise this year is if Andy Dalton or Justin Fields has help. A-Rob is a true No. 1 WR, and losing him would put way too much pressure on guys like Darnell Mooney, Anthony Miller and Marquise Goodwin.

Allen Robinson
NYG • WR • #15
REC YDs1250
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Dallas Cowboys: OT Tyron Smith

This should be a bright red warning sign for the 2021 Cowboys season, because Smith hasn't played a full season in six years, missing all but two games in 2020 due to lingering neck issues. He's still a good left tackle when healthy, but that's rarely. And guess what the top priority is for Dallas this year? Protecting Dak Prescott's own health up front.

Denver Broncos: OT Garett Bolles

After a surprise emergence as one of the NFL's sturdiest at his position, Bolles suddenly looks like a necessity as Denver banks on the contingent of Teddy Bridgewater and Drew Lock under center. The Broncos have an underrated roster, so they can weather injuries at spots like RB, WR and on defense, where they stocked up for Vic Fangio.

Detroit Lions: C Frank Ragnow

Devoid of premium playmakers on both sides of the ball, the Lions' only shot at maximizing the Jared Goff reclamation project is giving the QB a clean pocket. Left tackle Taylor Decker is another fair candidate then, but Ragnow is responsible for every snap exchange, as well as clearing lanes for what figures to be a heavy ground game under Dan Campbell, Anthony Lynn and Duce Staley.

Green Bay Packers: CB Jaire Alexander

You can make a real case for Davante Adams here, because Aaron Rodgers' best path back to a Super Bowl includes having his No. 1 wideout. But if Rodgers is around, we know he can do more with less than most. Alexander, on the other hand, is the Packers' only true cover man. Imagine relying solely on Kevin King and rookie Eric Stokes to fend off title contenders in the playoffs.

Houston Texans: OT Laremy Tunsil

Their only path to sniffing something other than a bottom-five record is giving their QB -- whomever that may be -- a respectable pocket, which only happens if the big-money left tackle is there to help.

Indianapolis Colts: OG Quenton Nelson

Eric Fisher is already an injury concern at left tackle, but Nelson is like the engine -- mentally, physically, etc. -- of their esteemed O-line. Without him, new QB Carson Wentz might be forced to freestyle way more than Frank Reich would prefer, leading to some of the same issues that plagued the former MVP candidate in his last season in Philadelphia.

Jacksonville Jaguars: C Brandon Linder

Linder has quietly been an anchor at the heart of the Jags' O-line, and nothing's more important this year than keeping Trevor Lawrence on his feet. Maybe someday, if they actually acquire consistent difference-makers at the skill spots, it'll be someone else.

Kansas City Chiefs: TE Travis Kelce

After the Super Bowl, you might be tempted to point to the O-line, but after adding Orlando Brown Jr., Joe Thuney, Creed Humphrey and Kyle Long, they are better positioned to handle an injury at any of those spots. Tyreek Hill going down would severely threaten their WR depth, but Kelce has long been Patrick Mahomes' favorite target, and that counts for a lot. 

Travis Kelce
KC • TE • #87
REC YDs1416
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Las Vegas Raiders: OT Kolton Miller

After already shuffling their O-line, they can't afford to have Derek Carr running for his life or Josh Jacobs running into brick walls in the trenches. Their defense is so porous that, quite frankly, it won't matter much whether a current starter is forced out.

Los Angeles Chargers: OT Rashawn Slater

Losing guys like Keenan Allen or Austin Ekeler or Joey Bosa would hurt big time, but much like Jacksonville, the Chargers have one job above all: Keep the young QB healthy. Justin Herbert just needs a steady hand at left tackle to sit comfortably and let his arm do the rest.

Los Angeles Rams: OT Andrew Whitworth

Like the Cowboys, maybe we should be more concerned about the Rams considering what this means: Whitworth, whose presence as Matthew Stafford's blind-side blocker is paramount to Los Angeles taking a leap, missed seven games in 2020 and will turn 40 in December. Lest we forget that Stafford wasn't always an elite QB in Detroit when he was facing the heat every week.

Miami Dolphins: CB Xavien Howard

Did anyone else forget that this guy picked off 10 passes in 2020? And seven in 2018? The Dolphins definitely have a lot riding on Tua Tagovailoa's development under center, so the O-line and new weapons -- chiefly rookie wideout Jaylen Waddle -- are important. But Howard's ball-hawking can easily be taken for granted in Brian Flores' respected defense.

Minnesota Vikings: WR Justin Jefferson

This one's tough, because as much as RBs are replaceable, Dalvin Cook basically makes Mike Zimmer's preferred offense. New left tackle Christian Darrisaw is almost equally as important, unless Minnesota is prepared for another bout of Kirk Cousins mishaps. And Danielle Hunter is still underrated at pass rusher. But man, if Jefferson's play-making pop is gone, the Vikings would be left with Adam Thielen and not much else in a passing league.

Justin Jefferson
MIN • WR • #18
REC YDs1400
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New England Patriots: OT Isaiah Wynn

Matt Judon is probably more key to their pass rush than most think, and Stephon Gilmore is still a lock-down option at corner. If you think Bill Belichick's ticket back to the playoffs is a restored defense, those guys carry even more value. But neither Cam Newton nor Mac Jones will have a shot at any meaningful production if the line can't hold up, and Wynn, at LT, is in the most important spot.

New Orleans Saints: RB Alvin Kamara

Their WR depth isn't great, so losing Michael Thomas would be a major hit to Jameis Winston's bid to be Drew Brees' long-term successor. But losing Kamara would be even bigger, even though Latavius Murray is a quality fill-in, because he's one of the game's ultimate safety valves -- a more explosive Christian McCaffrey. Cameron Jordan and Marcus Williams would be big losses, too.

Alvin Kamara
NO • RB • #41
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New York Giants: RB Saquon Barkley

This one'll have some people up in arms, in part because Barkley's a RB and in part because he's been on a downward trend, physically and statistically. Both Leonard Williams and James Bradberry are arguably more important to what they're doing, especially on an underrated defense. But 2021 is about helping Daniel Jones as much as possible, and few things would do that more than a healthy, recharged Barkley, who can contribute as both a power runner and pass-catching playmaker.

Saquon Barkley
PHI • RB • #26
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New York Jets: OT Mekhi Becton

It's simple: Rookie QB Zach Wilson needs to feel comfortable. He's already entering with a tendency to improvise, and losing his big left tackle would almost assuredly force him into some unnecessary shots.

Philadelphia Eagles: WR DeVonta Smith

Jalen Hurts can weather pressure better than Carson Wentz did at the end of his Eagles career, but he absolutely needs playmaking help, and Philly has sorely lacked a No. 1-type wideout. If you're looking for an alternative, Darius Slay is pretty much the only sure thing at cornerback, where the Eagles are banking on young reserves to step up.

DeVonta Smith
PHI • WR • #6
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San Francisco 49ers: OT Trent Williams

They have a whole litter of guys you don't want to miss: George Kittle, Nick Bosa, Fred Warner. Maybe it feels like so many because we're fresh off an injury-riddled 2020 in San Francisco. But for the sake of Jimmy Garoppolo and/or Trey Lance, few things are as important as Grade-A protection, and Williams provides just that at left tackle.

Seattle Seahawks: WR DK Metcalf

We all know Russell Wilson can escape issues up front. And Tyler Lockett is equally as important to No. 3 out wide. But Metcalf brings so much to the table whenever he takes the field, even scaring opponents with his physicality alone.

DK Metcalf
SEA • WR • #14
REC YDs1303
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Pittsburgh Steelers: OLB T.J. Watt

Rookie RB Najee Harris might actually fit here, considering how much Pittsburgh is banking on him solving its ground game. Minkah Fitzpatrick, Joe Haden and Cam Heyward are all vital on "D." But if it's not going to be on the O-line, which is already more of a mess than most realize regardless of any future injuries, the obvious choice is Watt. With Bud Dupree gone, there's more pressure on him to live up to his All-Pro reputation and keep the Steelers after opposing QBs.

T.J. Watt
PIT • OLB • #90
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Tampa Bay Buccaneers: OT Tristan Wirfs

Donovan Smith protects Tom Brady's blind side, but Wirfs is arguably the better lineman, and his role at RT throughout 2020 was instrumental in Brady winning yet another Super Bowl. Losing him would throw a major wrench into a title-winning front -- even more so than, say, the absence of other young standouts like Antoine Winfield Jr.

Tennessee Titans: RB Derrick Henry

An A.J. Brown injury would decimate their already-thin WR depth, but Henry literally runs their offense. Without his monstrous physicality and bruising mentality, Mike Vrabel would be forced to turn to a stable of unproven or underwhelming reserves, or ask Ryan Tannehill to become far more of an independent playmaker.

Derrick Henry
BAL • RB • #22
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Washington Football Team: WR Terry McLaurin

Does Chase Young mean more to this team in the short and long term? Maybe. But think about it: Ron Rivera's specialty is defense, and he's already got other mean men on the D-line. Conceivably, he'd be able to coax at least competent play from that unit without his top pass-rusher. On the flip side, even though Curtis Samuel and Dyami Brown give them exciting depth at WR, the whole point of bringing in Ryan Fitzpatrick at QB is to unlock the big play, in which McLaurin specializes as the obvious No. 1.

Terry McLaurin
WAS • WR • #17
REC YDs1118
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