Davis said he has limited movement in his shoulder — he didn't say which one — but said it shouldn't prevent him from playing because there's little chance of him doing further damage.
"Right now, it's OK," Davis said. "But right now, the situation we're in, we've got to suck it up and go."
Davis is a nine-year NFL veteran, who signed with the Bills this offseason to serve as the defensive play-caller as the team made the switch to a 3-4 defense. Buffalo is off to an 0-4 start, and its defense has struggled against the run in allowing a combined 473 yards rushing in its past two games.
Davis said he was initially hurt in a season-opening 15-10 loss to Miami. He said he aggravated the injury further in a 38-30 loss at New England on Sept. 26, which forced him to miss last weekend's game against the New York Jets.
Coach Chan Gailey didn't provide an update on Davis except to say he was expected to practice.
Defensive end Marcus Stroud returned to practice after missing last week's game with a left ankle injury. Stroud said he expects to play this weekend.
Safety Bryan Scott (knee), linebacker Keith Ellison (knee), linebacker Arthur Moats (elbow) and cornerback Ashton Youboty (hamstring) didn't practice. Starting cornerback Terrence McGee has already been ruled out after having minor knee surgery last weekend.
Tight end Shawn Nelson returned to practice after serving a four-game suspension for violating the NFL's substance abuse policy.
Gailey said the Bills have the NFL's approval for a one-week roster exemption after Nelson had groin surgery four weeks ago. Despite the exemption, Gailey hasn't ruled out Nelson from playing Sunday.
Anderson originally signed with the team in August to fill in after both Lynch and Fred Jackson were injured. He had 2,009 career yards and 17 touchdowns at Tulane.
Anderson gives the Bills a third running back behind Jackson and rookie first-round pick C.J. Spiller.
The Bills also announced they've released tight end Joe Klopfenstein from injured reserve.
To fill Anderson's spot on the practice squad, Buffalo signed defensive end Ra'Shon Harris. At 6-foot-5 and 300 pounds, Harris appeared in two games with Carolina last season. He was released by Pittsburgh this past summer.