PITTSBURGH - Football coaches traditionally call an offensive formation with three running backs a full house because, well, everybody's at home.

Everybody was at home in the Pittsburgh Steelers' backfield when practice resumed Monday following their bye weekend, and that means it could be crowded for next Monday's game at San Diego. Perhaps too crowded.

Willie Parker is healthy and No. 10 in NFL rushing despite having last weekend off. Duce Staley is healthy and practicing again despite needing knee surgery during training camp. Jerome Bettis is healthy and practicing again despite injuring a calf during camp.

Parker had the backfield pretty much to himself for the first three games, with Staley not healthy enough to play until the Sept. 25 game against New England - though he didn't get any carries in the 23-20 loss - and Bettis not ready until last week.

But with all three ready to go, and only one football per play to hand them, coach Bill Cowher must decide who is playing and who is sitting. With backup running back Verron Haynes needed as the third-down back and on special teams, it's possible either Bettis or Staley - most likely, Bettis - could be deactivated Monday night. Neither plays special teams, a key criteria for coaches in deciding which players to activate.

Bettis, the No. 5 rusher in NFL history, has never been a healthy scratch since joining the Steelers in 1996. But with Parker averaging 109 yards per game, despite being held to 55 yards by New England, he isn't about to leave the lineup.

"I don't think it's going to be tough," Parker said, diplomatically, when asked how all the backs would stay active. "They're going to put us in position to make plays, and they will be the best plays for the team."

Bettis seems to be the most logical to sit down, if only because he is the most recent to regain his health. Also, the plan before Staley and Bettis got hurt was for Staley to start - as he did at the beginning of last season - and for Bettis to be the backup.

Cowher didn't talk to reporters Monday, but likely will address the subject today.

Most of the Steelers players watched San Diego's 41-17 victory Sunday at New England, one that certainly got their attention because of the Chargers' 24-0 edge during the second half.

Several players joked that they deserved some of the credit for softening up New England during their physical game the week before, one in which the Patriots lost two key starters - safety Rodney Harrison and offensive tackle Matt Light - with serious injuries.

"That was a physical football game, with a lot of plays, and the Patriots lost a lot of good players, and then had to play San Diego," defensive end Kimo von Oelhoffen said. "New England's really banged up, and San Diego really controlled their defense."

San Diego (2-2), in the league's bottom third defensively but one of its best against the run, limited Corey Dillon to 63 yards - the fourth consecutive game he's been held well below his 107 yards average of last season. The Chargers' LaDainian Tomlinson ran for 134 yards and two touchdowns, and Drew Brees threw for 248 yards and two scores.

"One thing with that running back, the way he runs, we definitely have to be disciplined," linebacker Larry Foote said.

The Steelers (2-1) blitzed repeatedly against Patriots quarterback Tom Brady, a tactic that seemingly wouldn't work as well against Tomlinson. But Foote suggested that's exactly what defensive coordinator Dick LeBeau might do.

"We're going to be doing some blitzing, because that might help keep him in the backfield blocking, instead of trying to release," Foote said. "I'm quite sure coach LeBeau is going to have something good for them.

Meanwhile, wide receiver Hines Ward (hamstring) didn't practice, but said there's no chance he won't play.