Published: Aug 07, 2010 11:26 PM EDT
Updated: Aug 08, 2010 4:30 AM EDT

TORONTO (AP) — The Tampa Bay Rays have activated right-hander Andy Sonnanstine off the 15-day disabled list and optioned right-hander Dale Thayer to Triple-A Durham.

Sonnanstine will start against Toronto on Sunday in place of right-hander Jeff Niemann, who has a sore shoulder. It will be the first start of the season for Sonnanstine, 2-0 with a 4.22 ERA in 30 relief appearances.

Sonnanstine went on the disabled list last Sunday, retroactive to July 23, with a strained left hamstring.

Niemann, 10-3 with a 3.12 ERA in 22 starts, felt pain after beating Minnesota on Tuesday and was still sore after playing catch Saturday. Manager Joe Maddon said he hoped Niemann would only miss one start.

Tampa Bay announced the moves after Saturday's 17-11 loss at Toronto.