KICKOFF: Sunday, 1:00 ET
TV: FOX (Ron Pitts, Tony Boselli, Charissa Thompson)
SERIES: 10th regular-season meeting. The Bills lead the regular-season series 5-4. The Bills won the last meeting between the teams, 41-7, late in the 2004 season. The 49ers' last trip to Buffalo was in 1998, when they lost 26-21.
PREDICTION: Bills 19-17
KEYS TO THE GAME: 49ers coach Mike Singletary is looking at the expected cold conditions as a chance to test the character of his team. The first priority will be to establish RB Frank Gore and the ground game, and Singletary has challenged his offensive line to be physical and lead a power running attack. Hill is playing well, but the 49ers would prefer to run the offense through Gore and have him set up Hill to work off play-action. ... The 49ers' already shaky secondary is thinned by some injuries and will be vulnerable to big plays. But the Bills also don't want to do the 49ers any favors on a cold winter day. It's critical for QB Trent Edwards to avoid turnovers that set San Francisco up with short fields. With the ground game slowly coming to life, look for the Bills to turn to RBs Marshawn Lynch and Fred Jackson early to soften up the 49ers for more downfield shots later in the game.
KEY INJURIES: 49ers: WR Arnaz Battle (foot) is unlikely to play; CB Walt Harris (hamstring) is uncertain; WR Josh Morgan (groin) is out. Bills: TE Robert Royal (hamstring) and SS Donte Whitner (shoulder) are day-to-day; CB Jabari Greer (knee) and DE Aaron Schobel (foot) are unlikely to play.
FAST FACTS: Since the start of the 2003 season, the 49ers are 9-36 on the road overall and 3-27 in road games that began at 10 a.m. Pacific time. ... Clements ranks ninth in Bills history with 23 interceptions from 2001-06.
--P Andy Lee, who was named to the NFC Pro Bowl team last season, ranks tied for sixth in the NFL with a 47.2-yard average this season. Lee has the longest punt in the league this season, an 82-yarder. It is the third-longest punt this decade.
--LB Patrick Willis ranks second in the NFL this season with 97 tackles, according to the stats taken from game books and tracked by the Elias. Cleveland's D'Qwell Jackson leads the league with 108 tackles. Willis ranks first among all linebackers in the league with nine passes defensed.
--QB Shaun Hill has compiled passer ratings of better than 100 in five of the seven NFL games in which he has played in his career. In his past two games, Hill has completed 36 of 53 passes for 516 yards with four touchdowns and one interception.
--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.
--QB Trent Edwards has completed 204 of 303 passes this year, a 67.33 completion percentage that ranks second all-time in Bills history. Kelly Holcomb set the mark of 67.39 (155 of 230) in 2005.
--WR Lee Evans is hoping to repeat past success against the San Francisco 49ers. As a rookie in 2004, he caught eight passes for 92 yards and two touchdowns in a 41-7 Buffalo victory over the 49ers at Monster Park. Evans needs one 100-yard game to tie Frank Lewis (14) for fourth most in Bills history.
--TE Robert Royal is nursing a hamstring pull suffered last week against Kansas City. He's likely a game-time decision for Sunday's tilt with San Francisco.
--SS Donte Whitner is practicing on a limited basis this week due to his tender right shoulder. It's partly a pain tolerance issue and signs are leading towards him playing Sunday against San Francisco.
--CB Jabari Greer, who suffered a sprained knee against Cleveland and missed the Kansas City game last week, is still sidelined. He may be another game or so.
--LB Keith Ellison, who has been playing on a tender ankle, re-injured the joint in last week's win at Kansas City. He's day to day for Sunday's game against San Francisco.
--CB/KR Leodis McKelvin needs just 66 kickoff return yards to break Eric Moulds' rookie team record of 1,205 yards. McKelvin is averaging 29.2 yards per return.
INSIDE THE CAMPS
Clements is likely to be back battling the conditions at Ralph Wilson Stadium as the 49ers' punt returner. Clements is expected to get the assignment with regular return man Allen Rossum out of action with an ankle sprain. Clements returned a career-high 35 punts while playing for the Bills in 2004.
"I don't think it's going to be as bad as I've seen it there before," Clements said. "But you definitely have to concentrate and focus on catching the ball."
Clements has handled five punts this season for the 49ers with an 8.6-yard average. His big assignment Sunday will most likely be his coverage of Bills top wideout Lee Evans, who averages 19.3 yards on his 42 receptions.
Clements is looking forward to erasing the memory of last week's game.
"Last week's game?" Clements said. "I'm focused on moving forward. As a corner, you have to look at it as water off a duck's back - let it just roll right off you. You have to get ready for next week."
Owens torched the 49ers for 213 yards and a touchdown on seven receptions. Most of those yards came at the expense of Clements, who is in the second year of a lucrative contract with the 49ers after leaving Buffalo as a free agent.
49ers interim coach Mike Singletary said he had no regrets about matching up Clements on Owens.
"It wasn't a mismatch," Singletary said. "I think Nate Clements can cover T.O. If we just said, 'Nate Clements, go over there and get on the line of scrimmage and do not let him off the line of scrimmage,' I would say nine out of 10 times, Nate Clements would go over there and do that.
"(But) that's not the way we play defense. That's not the way we played it because they (the Cowboys) have so many other guys that can hurt you."
The San Francisco 49ers' defense ranks 23rd in the NFL in yards allowed, 29th vs. the pass and 29th in points allowed. So why is Bills quarterback Trent Edwards worried? Two numbers: 3 and 4.
San Francisco employs a 3-4 scheme that has given him so much trouble this season, and the 49ers have enough playmakers to potentially make his life miserable for three hours on Sunday at Ralph Wilson Stadium.
All three teams in the AFC East play a 3-4 -- the Dolphins, Jets and Patriots -- and Buffalo is 0-3 against those division rivals. Edwards struggled mightily in those games with turnovers and errant throws, contributing to a four-game losing streak that dropped Buffalo from a 5-1 team to .500 before it won at Kansas City last Sunday. Buffalo did beat San Diego, another 3-4 team from the AFC.
How does San Francisco stack?
"They have two shutdown corners (Nate Clements, Walt Harris) and two fast and physical inside linebackers (Takeo Spikes, Patrick Willis) that fly around to the ball and they disguise a lot of their coverage and fronts," Edwards said. "Again, this is what we faced with the AFC East defenses and that's very concerning to me right now."
Bills coach Dick Jauron is hopeful that familiarity breeds success, not more contempt.
"You hope so," Jauron said. "Obviously, the more you see and the more you experience it, you get a better and better feel for it. This team, I don't know if you saw their game against Dallas, but I have great respect for Dallas football team and they gave Dallas all they could handle. Tony Romo and Dallas made big plays to beat them. But they pressured and they played hard. They come after you. They're a talented group and we'll definitely have our hands full."
San Francisco - with four of its last six games on the road - lost to the Cowboys 35-22.
Buffalo didn't run the ball with any consistency in going 0-3 against the division, so that's a place to start Sunday. A good running game would give Edwards a play-action presence. In that way, he can get the 49ers reacting to him instead of the other way around.
"We've faced 3-4s and we've seen what a majority of their defenses can do," he said.
"Hopefully, we can handle it. The past couple of weeks the 49ers haven't shown as much defensively as they had earlier in the season, but again, I've said this about past defenses that they don't show a lot (either) and then once we play them, they bring the kitchen sink."