Minnesota Vikings running back Adrian Peterson (28) is helped up after injuring his knee during the second half of an NFL football game against Washington Redskins in Landover, Md., Saturday, Dec. 24, 2011.
Rashard Mendenhall, RB, Pittsburgh Steelers
The Silver and Gold's playoff hopes took a big hit when they lost their star running back in Week 17 to a torn ACL. As a result, he will miss the entire postseason and probably longer.
Adrian Peterson, RB, Minnesota Vikings
A dreary Vikings season got even worse Saturday when star running back Adrian Peterson (being helped off the field) tore the ACL in his left knee in a road victory over the Redskins. Other reports say he also tore his MCL. Peterson said he knew ''it was something bad'' the moment he was hit, and that he was in ''severe pain'' as he lay on the field. He was hurt when tackled by Redskins safety DeJon Gomes at the end of a 3-yard gain on the first offensive play of the second half.
Joey Porter, LB, Arizona Cardinals
The Cardinals put four-time Pro Bowl linebacker Joey Porter on injured reserve Wednesday, ending his season and putting his career in jeopardy. The 34-year-old, a member of the Steelers All-Time Team and the NFL 2000s All-Decade Team, started the first six games of the season but missed the next eight with a knee injury that required surgery.
DeMarco Murray, RB, Dallas Cowboys
The Cowboys star rookie running back DeMarco Murray was placed on injured reserve, ending his season after suffering a fractured ankle. Dallas has signed veteran running back Sammy Morris to replace Murray.
Jim Leonhard, S, New York Jets
New York Jets placed their starting safety Jim Leonhard on injured reserve after suffering a torn patellar tendon.
Marcus McNeill, LT, San Diego Chargers
Marcus McNeill was placed on the injured reserve after missing the last two games with a neck injury. McNeill, who has appeared in multiple Pro Bowl’s, will be replaced by Brandyn Dombrowski.
Sidney Rice, WR, Seattle Seahawks
Seattle Seahawks wide receiver Sidney Rice was placed on the injured reserve after suffering multiple concussions.
Scott Fujita, LB, Cleveland Browns
Cleveland Browns outside linebacker Scott Fujita was placed on the injured reserve with a broken hand.
Matt Leinart, QB, Houston Texans
Matt Leinart will undergo surgery to repair a fractured collarbone, which will end his season. Rookie T.J. Yates will replace Leinart at quarterback .
Michael Clayton, WR, Giants
Used primarily on special teams, Clayton will need surgery for a torn meniscus and was placed on injured reserve.
Jahvid Best, RB, Lions
Detroit's young star battled concussion symptoms for several weeks before the team gave up and decided to place him on injured reserve.
Derek Cox, CB, Jaguars
The Jaguars defensive back suffered a knee injury and was just the latest in a sequence of season-ending losses in Jacksonville.
Mark Clayton, WR, St. Louis Rams
Mark Clayton landed on the injured reserve with a knee injury. The Rams will rely on the play of Brandon Lloyd and Brandon Gibson.
Fred Jackson, RB, Buffalo Bills
Fred Jackson was placed on the injured reserve with a fracture to his fibula. Jackson, who was closing in on a 1,000-yard season, will be replaced by running back C.J. Spiller.
Matt Schaub, QB, Houston Texans
The Texans officially ended Matt Schaub’s season, placing him on the injured reserve. Schaub, who is suffering from a foot injury, reportedly will have surgery leaving no chance to return for a potential playoff run.
Donald Jones, WR, Buffalo Bills
The Bills placed wide receiver Donald Jones on injured reserve after sustaining a high-ankle injury against the Dolphins in Week 11.
Matt Cassel, QB, Kansas City Chiefs
Matt Cassel was placed on the injured reserve after suffering a hand injury. Backup quarterback Tyler Palko will replace Cassel.
Dan Williams, DT, Arizona Cardinals
The Arizona Cardinals placed Dan Williams on injured reserve in Week 11 after suffering a broken arm. Williams, who was Arizona's first-round pick in 2010, had played in every game this season.
Rodger Saffold, OL, Rams
St. Louis' starting tackle was placed on injured reserve thanks to a torn pectoral muscle. The rub of this injury was that it happened while Saffold was lifting weights.
Gabe Carimi, OL, Bears
Chicago's top draft pick went down with a dislocated knee in Week 2. He attemped to make a comeback, but a setback forced him to have surgery on Nov. 11.
James Carpenter, T, Seattle Seahawks
The Seahawks placed its first-round tackle on injured reserve, Wednesday. James Carpenter, who has exceeded expectations in his rookie season, tore his anterior cruciate ligament during practice.
Kris Dielman, G, San Diego Chargers
The Chargers’ Pro Bowl lineman was placed on injured reserve because of lingering concussion symptoms. Dielman, who suffered a concussion in a Week 7 game against the New York Jets, had a seizure on the flight home to San Diego and hasn’t returned to the field since.
Matt Schaub, QB Texans
How much time will he miss? Who knows at this point. Houston's star gunslinger is on the shelf with a reported Lisfranc injury, which ordinarily causes serious harm to the midfoot area.
Leon Hall, CB, Cincinnati Bengals
The Bengals placed Leon Hall on the injured reserve after tearing his Achilles tendon in his left leg. Hall, who was drafted in the first round of the 2007 NFL draft, hasn’t missed a game since entering the league.
Leonard Hankerson, WR, Redskins
Poor guy. Hankerson was making his second career start and had caught eight passes for 106 yards in Week 10 when he suffered a dislocated hip and torn labrum. He landed on injured reserve.
Chris Williams, LG, Chicago Bears
Chris Williams underwent surgery to repair a dislocated wrist which will end his season. The Bears will turn to Edwin Williams to replace Williams.
Eric Wood, C, Buffalo Bills
The Buffalo Bills starting center will miss the rest of the season after tearing a ligament in his right knee.
Knowshon Moreno, RB, Broncos
After coming back from an injury, Moreno tore his ACL against the Chiefs in Week 10. He was placed on injured reserve.
Kyle Williams, DT, Bills
The Buffalo Bills placed Pro Bowl defensive tackle Kyle Williams on injured reserve. Williams, who suffered from bone spurs in the foot, was given a contract extensions earlier in the season.
Gerald McCoy, DT, Buccaneers
2011 is a snakebit season for the Tampa youngster, as he returned from missing two games and tore a biceps muscle in Week 9 against the Saints. It's the second straight year that McCoy's season has ended early.
Daniel Sepulveda, P, Steelers
Don't kid yourself, punters can also get hurt. The left-footed kicker injured his plant leg during practice in Week 9 and was placed on injured reserve.
Larry English, LB, San Diego Chargers
The Chargers put linebacker Larry English on injured reserve with a foot injury. English, who was a 2009 first-round pick, has suffered many setbacks in his short career.
Kerry Collins, QB, Indianapolis Colts
The Colts placed veteran signal-caller Kerry Collins on injured reserve with a concussion. Collins started three games for the Colts, but hasn’t played in a game since Week 3.
Chris Cooley, TE, Redskins
Cooley, who has been nursing a knee injury and a broken index finger, was placed on injured reserve. Cooley’s future with the franchise could be in questions, as Fred Davis has blossomed as a mainstay.
Shawne Merriman, LB, Bills
Merriman suffered an Achilles' tendon injury in Week 6 and the injury was bad enough for the Bills to place him on season-ending IR.
Tim Hightower, RB, Redskins
Tim Hightower was poised for a breakout season in D.C., but that's all over now. The talented back tore his ACL in Week 7 against the Panthers and will miss the remainder of the season.
Earnest Graham, RB, Buccaneers
ACL tears are all too common in the NFL. The latest victim hits Tampa Bay where it hurts: the backfield. Graham is reportedly out for the year.
Matt Shaughnessy, DE, Raiders
The Oakland Raiders placed DE Matt Shaughnessy on season-ending injured reserve with a shoulder injury.
Jeff Otah, T, Panthers
Carolina Panthers offensive tackle Jeff Otah was placed on the injured reserve for the third time in four seasons, stemming from back and knee injuries.
Jason Campbell, QB, Raiders
Jason Campbell suffered a broken collarbone against the Cleveland Browns in Week 6. He'll have surgery and could miss the rest of the season.
Josh Morgan, WR, 49ers
Josh Morgan suffered a broken bone in his lower right leg in the Week 5 match up against the Tampa Bay Bucs. Morgan, who has 15 catches for 220 yards and one touchdown, will miss the remainder of the season.
Mario Williams, LB, Texans
Mario Williams' transition from a defensive end in a 4-3 alignment to 3-4 outside linebacker was going well enough. He had five sacks in the Texans' first five games. But that fifth game was his last of the season. Williams suffered a torn pectoral muscle Oct. 9 in Houston's 25-20 loss to the Oakland Raiders, requiring season-ending surgery.
Getty ImagesBob Levey
Chad Henne, QB, Dolphins
Dolphins quarterback Chad Henne had season-ending shoulder surgery after going down in the first half of Miami's Week 4 loss to the Chargers. The promising Henne will miss the rest of the season.
Bradley Fletcher, CB, Rams
Fletcher reportedly was ruled out for the season after colliding with receiver Mike Sims-Walker in practice on Wednesday, Oct. 5. Fletcher reportedly tore his anterior cruciate ligament and will require surgery. St. Louis has lost three of its top four cornerbacks entering the season to injured reserve.
Danny Amendola, WR, Rams
The Rams reportedly have placed Amendola on the injured reserve list. after he suffered a torn triceps muscle. It's uncertain whether he will need surgery.
Eric Foster, DT, Colts
In one of the more gruesome injuries this season, the Indy defensive tackle suffered a dislocated ankle in Week 4 against the Bucs and had surgery a day later. Foster will miss the rest of the season.
Bryan Thomas, LB, Jets
Rex Ryan's best pass-rushing linebacker was lost for the season in Week 4, suffering a torn Achilles' tendon during the Jets' 34-17 drubbing at Baltimore. The timing couldn't be worse for the longest-tenured Jet, as the 10-year veteran is due to become a free agent after this season. It won't be easy for New York, either. When Ryan was asked the day after the injury who would replace last season's team leader in sacks, the coach replied, "I'm not ready to anoint anyone as the starter."
Bob Sanders, S, Chargers
San Diego Chargers cornerback Bob Sanders suffered a season-ending knee injury and was placed on the injured reserve in Week 4.
Melvin Bullitt, S, Colts
Indianapolis Colts safety Melvin Bullitt re-injured his shoulder in Week 2 and was placed on the injured reserve in Week 4.
Gary Brackett, LB, Colts
Indianapolis Colts linebacker Gary Brackett was placed on the injured reserve in Week 4 after undergoing season-ending shoulder surgery. Brackett suffered the injury in Week 1 and hasn't played since.
Kenny Britt, WR, Titans
Tennessee wide receiver Kenny Britt will reportedly undergo surgery on his right knee to repair torn ligaments. Britt, who will miss the remainder of the season, left on a cart after twisting his knee and falling to the turf.
Domenik Hixon, WR, Giants
After a dazzling circus catch on a Monday night game against the St. Louis Rams, Giants wide receiver Domenik Hixon will miss the remainder of the year. Hixon tore his anterior cruciate ligament in his right knee for the second straight season.
Roscoe Parrish, WR, Bills
Buffalo will have to do without one of its playmakers after Parrish hurt his left ankle in Week 2 against the Raiders. The team placed him on injured reserve two days later.
Luis Castillo, DE, Chargers
San Diego will have to make do without its starting defensive end for possibly the rest of the season after watching him suffer a broken tibia in Week 1.
Tony Moeaki, TE, Chiefs
A promising second-year tight end, Moeaki laid waste to Kansas City's plan for a high-flying passing attack when he went down with a torn ACL in the team's final preseason game. See you next season.
Dan Koppen, C, Patriots
The Patriots boast a strong group of offensive linemen, but it became considerably weaker when they lost their starting center. Koppen broke his left ankle during New England's season-opening victory.
Jon Beason, LB, Panthers
It was a bad scene for the Panthers when their stud linebacker was carted off in Week 1 against the Cardinals. The diagnosis: torn Achilles' tendon. The prognosis: Gone for the season.
Thomas Davis, LB, Panthers
Didn't Carolina's linebackers suffer enough? Apparently not. A week after Beason's season-ending injury, Davis' 2011 came to an end when he suffered his third torn ACL injury in less than two years. Ouch.
Peyton Manning, QB, Colts
How badly is Peyton hurt? Not sure. When is he coming back? Who knows? Manning's ongoing recovery from neck surgery in the Spring has everyone wringing their hands, since nobody knows when he'll be back on the field. Stay tuned.
Mikel Leshoure, RB, Lions
Over before it started. A highly regarded second-round draft pick, Leshoure's rookie season will have to wait after he tore his Achilles' tendon early in training camp.
Nate Kaeding, K, Chargers
If it can happen to a kicker, it can happen to anyone. Kaeding, the most accurate leg in the NFL history, tore his ACL on the opening kickoff of the season. Hopefully, he'll be ready to go in 2012.
Eric Berry, S, Chiefs
What was worse? Getting blown out by Buffalo or losing their star safety for the season with a torn ACL? Things are ugly in Kansas City.
Jamaal Charles, RB, Chiefs
One awkward step and Kansas City's hopes for a successful season might have flown out the window. The dynamic threat blew out his ACL during a road game in Detroit in Week 2.
Nick Collins, S, Packers
Thankfully, Collins only suffered a concussion after a frightening collision during the Packers' game against the Panthers. Collins was taken off the field on a stretcher and was later able to walk. However, we won't see him back this season.