Tight end Vernon Davis is anticipating changes, noting: "They're definitely going to have to make changes. We've got Crabtree back and have pretty much all our weapons. It's going to be exciting and interesting to see the changes they make to stop us. They can't leave us one-on-one the whole time."
Davis had just three receptions for 20 yards, and Anquan Boldin had only a 7-yard catch in the Sept. 15 loss at Seattle.
Crabtree had four receptions and no touchdowns in each of last season's games with the Seahawks, but he made a 41-yard catch that keyed a Dec. 24, 2011, win at Seattle.
"I can't wait to go out there and do what I can do," Crabtree said. "This week is a big week for us. With that (11-1) record, you're supposed to be the top team in the NFL. We'll see on Sunday. It gets you hyped. Now it's about me calming down. This is my second game. I can't wait to go and play."
Asked about a potential matchup with Seahawks cornerback Richard Sherman, Crabtree said this game is "not about one person or two people."
Staley wants to play Sunday
Left tackle Joe Staley vowed to play Sunday after practicing a second straight day with a Grade I sprain of his right knee's medial collateral ligament. "It still hurts. It's stiff. But it's something I can play through," Staley said. He's officially listed as questionable, and Harbaugh wants to see how Staley feels Saturday.
Blakeman's motley crew
Clete Blakeman, who's been involved in recent officiating controversies, will be Sunday's referee. He failed to call a penalty on Steelers coach Mike Tomlin for his sideline interference on Jacoby Jones' kick return on Thanksgiving. Only 2? weeks ago, Blakeman waved off a potential pass-interference penalty at the end of the New England Patriots' loss in Carolina.
Blakeman didn't go unnoticed in his past two 49ers games. Last season, he and his crew allowed 79 seconds to improperly run off the clock in the 49ers' 24-24 tie with the St. Louis Rams. In 2010, Blakeman ejected defensive tackle Justin Smith for making contact with umpire Garth DeFelice in a 34-7 loss at San Diego. Although Blakeman deemed Smith's act "intentional," the league did not fine Smith for his actions.