Smith admitted today that his recently separated right shoulder and a chronically strained forearm have contributed to his awful play in the past three games of the 49ers' seven-game losing streak.

"Without a doubt, I'm not throwing the same way I was the first three weeks, and last year," Smith said before sitting out part of practice to rest his forearm. "Trying to play through this is hard. ... I chose to go out there and play, thought I could, thought it would get better as the weeks go on, and it hasn't."

The former No. 1 draft pick even wondered aloud whether he should take a prolonged break to get his shoulder back in shape, perhaps for 2008.

"No excuses, I chose to go out there," Smith said. "If you asked me whether I'd do it again, that's the question. It's continued to linger, and that's the most frustrating thing for me."

Smith's candid discussion of his injury woes contradicted several recent statements by both Smith and coach Mike Nolan. Both have claimed the quarterback's injuries weren't serious enough to cause his inaccurate throws and the resulting lack of confidence in the third-year pro's abilities.

"I really thought I could try to play through this and help this team," Smith said. "I feel like I was making progress, but Monday night definitely did not feel good."

Smith went 12-for-28 with several horribly inaccurate throws in San Francisco's 24-0 loss to Seattle on Monday night, missing open receivers and showing poor mechanics. Though Nolan said earlier today that he expects Smith to be the 49ers' (2-7) starting quarterback Sunday against St. Louis (1-8), even Smith isn't sure that's a good idea.

"I wasn't trying to stir up anything," Smith said. "I thought that it would get better, and it's not."

Smith separated his throwing shoulder on a sack by Seattle's Rocky Bernard on the third play of San Francisco's loss to the Seahawks on Sept. 30. Smith sat out the next two games and the Niners' bye week, but returned sooner than expected against the New Orleans Saints on Oct. 28, with Nolan praising his quarterback's toughness.

But Smith's accuracy has been off noticeably since his return. He's 51-for-109 for 453 yards and three interceptions in the past three games, while his 48.7 completion rate and 57.2 passer rating this season are 30th among NFL quarterbacks — dead-last among all passers with enough action to qualify for league statistics.

Around the bye week in mid-October, Smith also developed a strained forearm with muscle spasms, affecting his release and even his ability to grip the ball. Smith believes his forearm weakened when he went back to practice after prolonged inactivity with his shoulder in a sling.

The decision to rush back into practice really did his shoulder "more harm than good," said Smith, whose latest MRI on Tuesday will be examined again by Dr. James Andrews, the noted sports orthopedist who concurred last month with the 49ers' diagnosis that Smith didn't need surgery.

But the combination of injuries has forced Smith to alter his mechanics, causing technical flaws in his delivery that have been spotted by several observers, including the San Francisco coaches who apparently have chalked it up to human error.

"That's the frustrating thing," Smith said. "You're so used to hitting your targets, and but to go out there the past three weeks — that's the frustrating thing, to not be the same player you were."

Smith has been roundly criticized for his poor play in the past three weeks, but he repeatedly denied the injury had anything to do with it. After his 17-for-38 performance in a loss at Atlanta, he refused to acknowledge any health problems.