ST. LOUIS (AP) -- Kyle Boller will make his first start at quarterback for the St. Louis Rams on Sunday as Marc Bulger rests his injured shoulder.
Coach Steve Spagnuolo said Friday that if Bulger dresses for the game, it will be as the third quarterback. Rookie Keith Null will be the backup.
Bulger did not throw during Friday's practice and is listed as questionable for the game at NFC West rival San Francisco (2-1).
"He took some snaps," Spagnuolo said. "He did some handoffs. We've got 48 more hours for the throwing part of it."
St. Louis (0-3) will try to end a 13-game losing streak, the longest in the NFL.
Bulger suffered a bruised rotator cuff on his right throwing shoulder during last week's 36-17 loss to Green Bay. Boller came in and threw two touchdown passes, but the comeback fizzled in the second half. Overall, he was 16 for 31 for 164 yards and an interception.
Boller is in his first year in St. Louis. He had 42 career starts for Baltimore, but Sunday will be his first start since Dec. 16, 2007. He missed last season with a shoulder injury.
He has taken all the first-team snaps in practice this week.
"You want him to play within his personality and you want him to make sure he does the little things right," offensive coordinator Pat Shurmur said. "We've constantly emphasized taking the easy ones and making sure we make the routine plays."
Boller feels he is ready.
"You've got to be confident in your abilities and, especially in this position, believe in yourself," he said. "I think it's a huge opportunity. We're looking to win a football game here. That's all I'm thinking about -- doing everything I can to lead this team to victory.
"I'm not worried about the future and how it goes. I'm worried about this game and this moment."
Boller is much more agile than Bulger and said that even with just two healthy quarterbacks he won't alter his style of play. He said he'll even throw a block if necessary -- just as he did last week to help Steven Jackson gain an extra couple of yards.
"I love doing that kind of stuff," Boller said.
Null, a sixth-round pick out of West Texas A&M, knows he is an injury away from getting his first regular-season action.
"I feel fine," he said. "I'm still preparing and I'm trying to be ready if they need to call my name."
The Rams also said safety James Butler (knee) won't play Sunday. The strongside linebacker starter has yet to be determined. David Vobora is out for four games because of a violation of the NFL drug policy, and Larry Grant and Paris Lenon are battling for the job.
(Copyright 2009 by The Associated Press. All Rights Reserved.)