"Jim Schwartz said he's "not 100 percent" decided on who his starting quarterback will be Sunday at San Francisco.

Rookie Matthew Stafford likely will remain sidelined with a left shoulder injury, but Schwartz declined to say whether Drew Stanton, who replaced Daunte Culpepper for the second half of the 31-24 loss to Arizona, would get his first NFL start.

"They'll be told by Wednesday," said Schwartz, who altered the team's schedule to give the players today off, followed by a walkthrough practice Tuesday.

The Lions coach did offer an assessment of Stanton's play. Stanton was 10 for 19 for 72 yards with an interception in the second half. He also scored a touchdown on a 1-yard quarterback sneak.

"Did some good things, did some not-so-good things," Schwartz said. "Moved the team, put points on the board. I think those are things that we had been struggling to do. We intercept a ball and score a touchdown, but after that we put 17 points on the board in a half of football. In the NFL, that's a good half of football. "