--WR Reggie Brown did not practice Thursday after injuring his groin late in Wednesday's workout. It's uncertain whether he'll be able to play Sunday against the 49ers.

--RB Brian Westbrook didn't practice for the second straight day. He has two fractured ribs. He hasn't yet been ruled out of Sunday's game, but there appears little chance of him playing.

--RG Shawn Andrews will miss his fourth straight game Sunday with back spasms. The injury doesn't appear to be getting much better, though surgery still isn't a consideration.

--DE Juqua Parker, who leads the team in sacks with 3 1/2, missed his second straight day of practice with knee swelling. He'll likely play Sunday, though his reps may be reduced.

--DE Victor Abiamiri will make his first appearance of the season Sunday after missing the first five games with a dislocated wrist. Abiamiri will play a little at end, but probably will be used mainly as a tackle in the nickel package.

GAME PLAN: In their three losses, the Eagles' defense has allowed opponents to convert 24 of 46 third-down opportunities. In their two wins: two of 24. They will try to do Sunday what they couldn't do last week against Washington, get the 49ers in third-and-long situations and unleash their blitz on inexperienced quarterback J.T. O'Sullivan. O'Sullivan has been sacked an NFL-high 20 times.

MATCHUPS TO WATCH: Eagles LBs Chris Gocong, Stewart Bradley and Omar Gaither vs. 49ers RB Frank Gore -- Gore leads the league in yards from scrimmage and is an excellent receiver out of the backfield.

Eagles LT Tra Thomas vs. 49ers DRE/OLB Justin Smith: Smith has three sacks, but Thomas is one of the league's best left tackles.

Eagles WR DeSean Jackson vs. 49ers CB Nate Clements: Jackson has 4.33 speed. Clements is one of the league's better cover men.

INJURY IMPACT: The Eagles' offense likely will be without Pro Bowl RG Shawn Andrews (back) and Pro Bowl RB Brian Westbrook (fractured ribs). WR Kevin Curtis, who missed the first five games (sports hernia), may play Sunday, but if he does, it would only be in a limited role.