Tigers GM Dave Dombrowski said right-hander Buck Farmer would take Lobstein's place in the rotation and start Thursday against the Los Angeles Angels, according to MichiganLive.com. He said Lobstein would undergo an MRI on his shoulder Sunday.
Lobstein, 25, has gone 3-5 with a 4.34 ERA and a 1.45 WHIP in eight starts. He's served as a replacement for Justin Verlander, who has a right triceps strain and has yet to appear this season.
"It's been something that's bothered him on and off," Dombrowski said of Lobstein. "You've seen that he hasn't felt quite up to par, has been able to pitch through it. ... We're hopeful that there's just some inflammation in there."
In a corresponding move, the Tigers recalled infielder Dixon Machado from Triple-A Toledo. The team will have to make room on the roster for Farmer for his Thursday start.
- Jeremy Woo