SANTA CLARA -- Mario Williams' left wrist is ailing, but the 49ers still are heaping respect on the Buffalo Bills' high-priced defensive end.

"He doesn't want excuses. He's a grown man," said right tackle Anthony Davis, who will match up against Williams on Sunday when the Bills (2-2) visit the 49ers (3-1).

One the NFL's biggest offseason moves saw Williams ditch the AFC favorite Houston Texans for the money-throwing Bills. He received the most guaranteed money ever for a defensive player, $50 million, as part of a six-year, $100 million deal.

So far, Williams has only 11/2 sacks, and he told Buffalo reporters Wednesday that he's frustrated with a wrist injury that's lingered since the exhibition finale.

"I'm a hands-on player, and it's all about power in my game," Williams said. "It's been odd having a little nick and not using it to the full extent."

Williams still is commanding multiple blockers, and offenses are moving the ball away from him, according to 49ers offensive coordinator Greg Roman, who added that he "didn't notice anything wrong" with Williams' wrist.

Williams has not appeared on the Bills' injury report all season, and coach Chan Gailey made no mention of Williams' wrist in Wednesday's conference call with Bay Area media. "He has ended up drawing two and three blockers quite a bit, so his statistics are not where they need to be," Gailey said.

Williams tallied two tackles and no sacks in Sunday's 52-28 loss to the New England Patriots, who shredded the Bills defense for 45 second-half points.

  • Bills quarterback Ryan Fitzpatrick leads the NFL with 12 touchdown passes. His 15 scrambles for 66 yards also have captured the 49ers' attention. "He'll create some of the same problems that (Christian) Ponder created in Minnesota with the scrambling ability. So, we'll have our work cut out with him," 49ers defensive coordinator Vic Fangio said.

  • Tucked inside quarterback Alex Smith's locker is a San Francisco Giants hat covered with autographs from the National League West champs. The 49ers' locker room isn't totally devoid of A's fans, however, as the Bay Area's other baseball team heads to the playoffs.

    Running back Anthony Dixon's brother, Rashun, just completed his fifth season as a Single-A outfielder in the A's farm system, splitting time this year between the Stockton Ports and Burlington (Iowa) Bees. "I can't say I'm on the bandwagon fully," Dixon said. "But there's a little bit in me."

  • Linebacker NaVorro Bowman practiced for a second straight day in a black, no-contact jersey, apparently because of a shoulder strain. It does not appear to be hindering him.

  • Cornerback Carlos Rogers (ankle) and nose tackle Isaac Sopoaga (knee, ankle) didn't seem too bothered by injuries that limited them in practice.

  • The 49ers have suffered defeats after each of their past three shutout wins, and five of their past six dating back to 2000. Last Sunday's 34-0 win over the New York Jets was the 49ers' first shutout this season.

    For more on the 49ers, see Cam Inman's Hot Read blog at blogs.mercurynews.com/49ers. Follow him on Twitter at twitter.com/CamInman.