Manager Joe Maddon said the big righty met with Dr. James Andrews and was told that Niemann may be able to start throwing "in a couple of weeks."
Niemann left Saturday's start, his first since coming off the DL, after 3 1/3 innings because of a mild right rotator cuff strain.
"He was checked out, and the doc said it wasn't that bad," Maddon said. "He felt like he could be throwing soon."
Maddon said he hasn't thought about giving Niemann extra work in the offseason but is afraid that if he did, Niemann could pile on too many innings going into the 2013 campaign.
Niemann hasn't been too lucky this season. His first six starts of the year went fairly well, but a comebacker that fractured his right fibula forced Niemann to leave his May 14 start against the Blue Jays after an inning. The injury resulted in a 3 1/2-month trip to the disabled list.
After Niemann made four rehab starts in August, the Rays activated the right-hander with the intention of using him in spot starts or in such a way that other starters would receive an extra day of rest.
Niemann is 2-3 with a 3.08 ERA in eight starts this season.