Lawson is a versatile player, yet he is the first 49ers' defender to come off the field when the 49ers go with extra defensive backs. Interim coach Mike Singletary said it is a priority to get Lawson increased playing time.

"We're trying to get him on the field more, and we will get him on the field more," Singletary said. "He deserves that. He's been doing that. But he's had to work toward that. It's not like Manny's been doing great all year and then all of a sudden, 'Why isn't he playing?' Obviously, we want to win, too."

PLAYER NOTES

--CB Donald Strickland might get his third start of the season on Sunday against the Buffalo Bills if veteran Walt Harris is unable to play. Harris sustained a strained right hamstring in the 49ers' game Sunday against the Dallas Cowboys.

--DE Justin Smith leads the 49ers with 39 quarterback pressures, but he has recorded only three sacks on the season. Smith has gone six games without a quarterback sack. Smith ranks fourth on the 49ers with 71 tackles, according to the team's film review.

--RB Frank Gore has dropped into a tie for fourth in the NFL with 1,191 yards from scrimmage after a game in which he had just 32 total yards against the Dallas Cowboys. Gore still leads the 49ers with 36 receptions.

--WR Isaac Bruce's two best games this season have come against Seattle and Dallas, as he combined for 278 receiving yards. For the season, Bruce has 558 yards and five touchdowns, as he has not been a consistent producer in the 49ers' offense.

--LB Larry Grant, the 49ers' only draft pick who did not make the 53-man roster, was signed off the team's practice squad and is now on the roster of the St. Louis Rams.

GAME PLAN: The 49ers expect a physical matchup Sunday against the Buffalo Bills. That fits into interim coach Mike Singletary's mindset, and he said his offensive line is ready to rise to the challenge. "When you look at our offensive line, they get excited about being a power running team," Singletary said. The 49ers must get some major production from running back Frank Gore if they have any hopes of being competitive against the Bills. If Gore is able to get some chunks of yards, it will make it easier on quarterback Shaun Hill to make effective play-action fakes in hopes of getting the ball down the field. Tight end Vernon Davis has caught just one pass in each of the past three games, but he is showing signs of being a viable option in the passing game. Those three passes have produced two touchdowns and one 47-yarder. Defensively, the 49ers have gone with more of a 3-4 scheme with coordinator Greg Manusky after Mike Nolan was fired as head coach. The team is settling into that defense to shore up the run game. However, the 49ers need to be able to bring more pressure from the pass rush. The 49ers rank 28th in the league in sacks per play. The 49ers have recorded just nine sacks in their eight losses this season.

MATCHUPS TO WATCH: 49ers RB Frank Gore vs. Bills MLB Paul Posluszny - Gore is the key to the 49ers' offense. Posluszny leads Buffalo with 94 tackles.

49ers RG Chilo Rachal vs. Bills LDT Marcus Stroud: Rachal struggled in his first career start a week ago against Dallas, and it won't get any easier this week. Stroud, an eight-year pro, is a force at clogging up the run game inside.

49ers OLB Parys Haralson vs. Bills LT Jason Peters: Haralson is tied for the 49ers' lead with three sacks. Peters got off to a slow start this season after a protracted contract holdout. But he's playing well again.

49ers LB Patrick Willis vs. Bills RB Marshawn Lynch: Willis leads the 49ers in tackles. Lynch, a fellow second-year player, is a threat in the run and pass games.

49ers CB Nate Clements vs. Bills WR Lee Evans: Clements is coming off a difficult game against the Cowboys' Terrell Owens. Evans is a game-breaking receiver who averages 19.3 yards per reception.

INJURY IMPACT: LB Patrick Willis has an ankle sprain that kept him out of practice early in the week. Willis is expected to start Sunday's game.

--WR Arnaz Battle is likely to miss another game with a mid-foot sprain. Battle has been out since Oct. 26 with the injury. He recorded 24 catches for 318 yards as the 49ers' slot receiver.

--CB Walt Harris returned to limited practice on Thursday, and his status for Sunday's game against the Bills is questionable with a hamstring strain. Harris has started every game this season.

--WR Josh Morgan (groin) returned to limited practice this week, but he is not expected to be well enough to play in Sunday's game.

--S Dashon Goldson (knee) will miss his fifth consecutive game.

--KR Allen Rossum (ankle) has already been ruled out of action for Sunday's game. Veteran Nate Clements will likely return punts, while Delanie Walker would take over on kickoff returns.