Rattay returned to practice Wednesday and threw for the first time without taking pain-blocking injections. He had no soreness Thursday and looked strong leading the offense in team drills.
"It felt great today," Rattay said. "I feel 100 percent. I was fired up that it wasn't sore and I felt like I was throwing a
lot harder and had a lot of zip. The ball is popping out of there like it used to."
Coach Dennis Erickson also noticed improvement. But he stopped short of naming Rattay the starter for Sunday night's game against the St. Louis Rams.
"He looked better today than he was yesterday," Erickson said. "He'll get better every day. We feel, unless there is some kind of temporary setback, that he'll have a chance to play on Sunday. He's getting back to where he was going into the Atlanta game."
Rattay separated his shoulder while being sacked in the second quarter against the Falcons and was replaced by Dorsey. Rattay returned after Dorsey was injured to throw two touchdown passes in the fourth quarter.
Rattay needed pain-blocking injections to be available as Dorsey's backup each of the past two weeks. Dorsey struggled in those two games. His passer rating of 59.5 is the lowest in the NFC.
Dorsey is nursing a minor groin injury he suffered last week against Seattle. Erickson said he'll wait until Friday or Saturday to name the starter, but he also added, "We're probably as healthy as we've been at quarterback going into this game."
Rattay made his first NFL start last year against the Rams in San Francisco. He threw three touchdown passes to lead the 49ers to a 30-10 upset.
The shoulder separation is Rattay's third significant injury this year. He had surgery in May after tearing a groin muscle during San Francisco's first spring minicamp practice. An inflamed forearm kept him out three weeks during training camp.
Rattay said it is "more than likely" he won't need an injection to play this week, and announced himself as healthy as he has been all year.
"The leg feels great. The arm's fine. I'm back to where I'm used to having it. I definitely say this is the best I've felt in a long time," Rattay said.