Rams coach Steve Spagnuolo hasn't ruled out Bulger, who has a bruised rotator cuff in his throwing shoulder. Bulger rode a stationary bicycle and did exercises along with safety James Butler and offensive tackle Jason Smith, both of whom are recovering from knee injuries.
"I know we wanted to shut him down today. That was the game plan so as not to aggravate it (the injury)," Spagnuolo said of Bulger. "I think after he gets his treatment and gets here in the morning, then we'll make another assessment."
Bulger believes there's a chance he could be ready to play against the 49ers, although he judged that it wouldn't have been pretty had he attempted to throw the ball Wednesday.
"It would have to be a major improvement, but I'm taking it day by day," Bulger said. "I think doing anything right now, at least today, would set me back to Sunday again.
"I'm trying to get it healthy as quick as I can, and if I can go, I'm going to go."
Bulger has sought a second opinion about the injury. He said any quarterback with a shoulder injury would do the same.
"It's not a reflection on anyone," Bulger said. "It's just another set of eyes."
Boller threw two touchdown passes during the second quarter last Sunday before the Rams' comeback fizzled in a 36-17 loss to the Green Bay Packers. Boller had 42 career starts for the Baltimore Ravens but missed all of last season following a shoulder injury.
Boller threw a block for Steven Jackson last week against the Packers and said he wouldn't alter that aggressive style if he made his first start since Dec. 16, 2007, even if the third-string quarterback is rookie Keith Null. Boller recalled Null reminding him to take it easy.
"He said, 'What are you doing?'" Boller said. "I said, 'I'm playing football, man.' That's my nature, I like doing that kind of stuff."
Boller said he played linebacker as a kid and takes that mentality onto the field.
"It's my time to take it out on them," he said. "Instead of being hit all the time, you get to actually hit them."
Whoever receives the call will work with a cast of unknowns at wide receiver. Laurent Robinson had emerged as the Rams' top wide receiver with 13 catches, a 12.8-yard average and three touchdowns after totaling just five receptions last season, but he was placed on season-ending injured reserve Wednesday with a high right ankle sprain accompanied by a fractured right fibula.
Donnie Avery, the only other Ram in double figures, has 10 catches for just a 6.2-yard average and has committed two costly turnovers.
"It's tough, but at the same time, that's football," Boller said. "Guys are going to be coming in and out. These guys are going to step up, and it's my job to make it as easy as possible on them and for them to make plays for me."
Copyright 2009 by The Associated Press