For all their early-season woes in 2011, the Kansas City Chiefs were still 4-4 and in the thick of a subpar AFC West race when starting QB Matt Cassel suffered a season-ending hand injury in a Week 9 loss to Denver.
Chiefs fans can criticize Cassel all they want (and a lot of it is deserved), but there's no doubt that the wheels came off when Tyler Palko took over as Kansas City's starting quarterback. Palko threw six interceptions and no touchdowns in his first two starts, a 34-3 humbling at the hands of the Patriots and a 13-9 loss to Pittsburgh. While he bounced back to beat Chicago, the Chiefs eventually felt desperate enough to make a move for Kyle Orton, who then started in Weeks 15-17.
The moral of the story: It pays to have quality depth on your roster. And even though training camps are just getting under way league-wide, plenty of teams find themselves dealing with injury concerns at key positions.
A look at some of the most important, and which players will get increased looks in camp as a result:
• Akeem Dent, MLB, Atlanta (Lofa Tatupu): When Curtis Lofton jumped ship as a free agent (for division rival New Orleans, no less), the Falcons rolled the dice by picking up the veteran Tatupu, who hasn't played a down since the 2010 playoffs. Now, it's on to Plan C after Tatupu tore a pectoral muscle last week -- an injury that has already ended his season. Dent, a third-round pick in 2011, will get first crack at taking the starting middle linebacker spot over. Working in his favor? There aren't a whole lot of other viable options on the Falcons' roster.
• Paul Kruger, OLB, Baltimore (Terrell Suggs): The Ravens have a lot of confidence in Kruger, which is a good sign because he might be one of the keys to their playoff hopes. Baltimore had him tabbed to take Jarrett Johnson's starting spot after Johnson headed to San Diego in free agency, but Terrell Suggs' Achilles tear left the Ravens in need of a pass-rusher. Kruger had 5.5 sacks in less than 400 snaps last season, so he has the potential to excel here. Still, Suggs' shoes are big ones to fill.
• Brandon Ghee, CB, Cincinnati (Dre Kirkpatrick, Leon Hall): The Bengals did not take Kirkpatrick No. 17 overall with the intention of easing him into the lineup, especially with Hall's slow return from an Achilles injury. The only problem there? Kirkpatrick injured his leg away from the team at some point recently, and the Bengals expect him to be out a month. On top of that, Nate Clements, Adam Jones and Shaun Prater have all missed time this spring with more minor injuries. All of this adds up to an opportunity for Ghee, the 2010 third-rounder who's coming off a great string of OTAs and minicamps, to stake a serious claim on the nickel corner job.
• John Hughes/Scott Paxson, DT, Cleveland (Phil Taylor): Hughes looked like a reach as a third-rounder in this year's draft, but the extended loss of Taylor to a torn pec could suddenly make him invaluable. Either Hughes or Paxson will have to pick up the slack up front in Taylor's absence. Cleveland finished 30th in run defense last year, so it badly needs an improved effort on the D-line.
• Kevin Smith, RB, Detroit (Jahvid Best/Mikel Leshoure): Nothing new to see here. Detroit plucked Smith off the scrap heap last year, and he rewarded the Lions by totaling more than 500 yards from scrimmage in seven regular season games -- though Smith, as has been his reputation, struggled to stay healthy. With Best still working back from a series of concussions and Leshoure coming off an Achilles tear (and suspended to start the year), Smith could see crucial minutes again. The Lions don't live and die by their run game, but they at least need a weapon out of the backfield.
• Travis Daniels, FS, Kansas City (Kendrick Lewis): It's a pec injury epidemic. Lewis had surgery for that injury in January and has slowly been making his way back. But with Lewis and Eric Berry (ACL) still on the shelf during OTAs, Daniels jumped onto the first-team defense, and should get some more starter snaps at least early in camp while Lewis continues to hit full-speed. Lewis started all 16 games last season, while Daniels was only adequate in limited duty.
• Toby Gerhart, RB, Minnesota (Adrian Peterson): Like with Kevin Smith in Detroit, the Vikings have been down this road before. Gerhart got five starts in Peterson's stead last season -- three while A.P. nursed an ankle injury; two after Peterson blew out his knee late in the year. Minnesota is hopeful Peterson can continue his speedy recovery and get back on the field early in the year, but the franchise cannot afford to rush him. So whether it's as a starter or a reserve giving Peterson some valuable rest, Gerhart will get his shots.
• Robert Gallery, G, New England (Logan Mankins): The Patriots expect to have Mankins back for the preseason, despite the surgery he underwent after the Super Bowl to repair a torn ACL. But just in case, New England signed Gallery after Seattle cut him loose. Gallery has been a colossal disappointment throughout his career, but as a safety valve here, the Patriots could do worse.
• Rueben Randle, WR, New York Giants (Hakeem Nicks): Nicks has stressed repeatedly that he'll be ready for Week 1 after breaking a bone in his right foot this offseason. Even if that's the case, the door is wide open for the Giants at WR during the preseason. Ramses Barden, Jerrel Jernigan and Domenik Hixon could all benefit in the race for New York's No. 3 receiver job, but the most intriguing candidate is Randle. The second-round pick out of LSU has the type of athleticism that could open some eyes in August.
• Eric Smith, S, New York Jets (LaRon Landry): If Landry is recovered from lingering Achilles injuries, the Jets found themselves a top-level option at safety. The problem is that Landry has not been able to stay healthy since 2009, so the Jets may have no choice but to slot Smith back into the lineup after starting 14 games last season -- and even if Landry's a full-go, Smith will see time. If you're a Jets fan, that might make you nervous: Smith was rated the team's worst defender in 2011 (by a wide margin) by Pro Football Focus.
• Demetress Bell, OT, Philadelphia (Jason Peters): The Eagles suffered a huge blow up front this offseason when Peters twice ruptured his Achilles. They moved quickly to snatch Bell off the free-agent market, but Peters had been to five consecutive Pro Bowls and was arguably the best tackle in football last season. If Bell can't hold his own, King Dunlap will be waiting in the wings.
• Isaac Redman, RB, Pittsburgh (Rashard Mendenhall): Steelers GM Kevin Colbert said last month that he expects Mendenhall to open the season on the PUP list as he continues to make his way back from an ACL tear. Redman rushed for a combined 213 yards in his two replacement starts in 2011 (Week 17, wild-card playoff round). He also averaged 4.4 yards per carry last year, a better mark than Mendenhall's 4.1. But can he carry the load for six-plus weeks?
• Ben Obomanu/Golden Tate, WR, Seattle (Sidney Rice): Rice had surgery on both of his shoulders this offseason and he's missed 15 of 32 regular season games over the past two years. Rice's questionable health just makes Seattle's WR situation even more fluid -- Obomanu, Tate, Doug Baldwin and Deon Butler are already fighting for one starting job; a slow recovery from Rice could open up a second.
• Michael Bennett, DE, Tampa Bay (Da'Quan Bowers): Bennett started 10 games at DE last season (compared to six for Bowers), so this isn't a "replacement" situation, per se. Still, the Bucs had high hopes for Bowers in his second season. Instead, they'll stick with Bennett, who re-signed as a restricted free agent this offseason. Without Bowers backing him up, Bennett must stay healthy and play well.Kendall Wright, WR, Tennessee (Kenny Britt): Titans