"He was really concerned when I went out there," Molitor said. "I don't want to say it was a pop, but it was something unnatural and it makes you think about the [rotator] cuff or something like that. But as far as his tests coming out of the game it seems more like a high lat strain. The shoulder tested fine. It was more of a pulling thing."
Pressly said it was hard to describe what it felt like, but that he overextended on the pitch. He also said it's too early to tell how serious the injury is.
"It wasn't fun, I'll tell you that much," Pressly said. "It was an unfortunate situation. I don't really know all the details yet. I'm just going to get an MRI tomorrow and it's just one of those things I can't explain right now."
Left-hander Aaron Thompson replaced him and was able to get Mike Moustakas to ground into a double play. Right-hander Blaine Boyer finished off the inning, getting Eric Hosmer to ground out after walking Lorenzo Cain.
Pressly has been solid this season since being recalled from Triple-A Rochester on May 1, posting a 2.93 ERA in 27 appearances. He's struck out 22 and walked 12 without allowing a homer in 27 2/3 innings.
Rhett Bollinger is a reporter for MLB.com. Read his
blog, Bollinger Beat, follow him on Twitter @RhettBollinger and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.