The injury bug continues to bite teams in the playoff hunt as the NFL calendar flips to December.
The Seattle Seahawks find themselves down a wide receiver - again - while the St. Louis Rams will take on a division rival with their starting running back ready to go. And Peyton Manning will have all of his offensive weapons at his disposal when the Denver Broncos face the Chiefs in Kansas City.
Here's a look at five of the most notable Week 13 injuries:
Jason Campbell, QB, Cleveland Browns (out, concussion)
Campbell was beaten up in last week's loss to the Pittsburgh Steelers, having his ribs bruised and suffering a concussion. The first injury didn't keep him out of the game, but the second one did - leaving the Browns with no other option than to put much-maligned Brandon Weeden back on the field. Campbell didn't practice all week and will sit this one out as Weeden gets the call. He'll be in tough against a Jacksonville team that has won two of its last three games after opening the season with eight consecutive losses.
Cleveland is a 7-point favorite against the visiting Jaguars, with the total at 39.5.
Percy Harvin, WR, Seattle Seahawks (doubtful, hip)
A stretch that started full of optimism has turned sour for Harvin, who is still dealing with the effects of his major off-season hip surgery. After seeing limited action in his season debut against the Minnesota Vikings two weeks ago, Harvin reportedly suffered a setback regarding his hip this week and has been downgraded as a result. Harvin will likely be given the week off to see how his injury responds, with Seattle still rolling atop the NFC West and far more interested in having Harvin healthy for the postseason.
Seattle is a 4.5-point favorite in the Monday nighter against visiting New Orleans. The total is 47.5.
Julius Thomas, TE, Denver Broncos (questionable, knee)
Knowshon Moreno, RB, Denver Broncos (probable, ankle)
It's a good-news kind of week for Manning and the Broncos, who are expected to have both Thomas and Moreno on the field for Sunday's pivotal showdown with the Chiefs. Thomas practiced on a limited basis for most of the week but showed no side effects from the knee injury that sidelined him for last week's overtime loss to New England. Moreno, who busted out for 227 rushing yards in that game, suffered an ankle injury late but practiced in full on Friday and declared himself good to go.
The Broncos are 5.5-point favorites in Kansas City, with the total at 49.5.
Zac Stacy, RB, St. Louis Rams (probable, concussion)
There were more than a few worried Rams fans after Stacy left last week's victory over the Chicago Bears with a concussion. But the rookie running back passed all the required protocols while easing himself into a bigger practice workload. He has been cleared to return this weekend, but will be in tough against a San Francisco defense that has allowed the sixth-fewest rushing yards in the league. Of note for the Niners is the return of wide receiver Michael Crabtree, who will appear in his first game since tearing his Achilles in the off-season.
St. Louis is 7.5-point underdog Sunday in San Francisco. The total is 41.