CHICAGO -- The Twins are unsure just how long they might be without their primary setup man after right-hander Pat Neshek left Thursday's game against the White Sox in the eighth inning with a right elbow strain.

The injury occurred after Neshek had allowed a single to Jermaine Dye and struck out Nick Swisher to start the inning. But it was on a slider he threw to the third batter he faced, Joe Crede, that Neshek appeared to hurt his elbow. Neshek immediately grabbed his arm after making the pitch.

"I felt something tweak," Neshek said of the injury. "It kind of rolled over real quick like a snap. I'll get it checked out [Friday] morning and make sure nothing happened."

Twins trainer Rick McWane and third-base coach Scott Ullger, who was acting as manager following Ron Gardenhire's ejection in the sixth inning, came out to the mound to check on Neshek. After a brief conversation with the two, Neshek exited the field with McWane. Right-hander Brian Bass, who did not have an opportunity to warm up beforehand, was then called on to take over for Neshek.

Standing at his locker after the game, Neshek said he could move his elbow but that some slight soreness was there. The Twins were heading back to Minnesota on Thursday night, and Neshek said the plan is for him to see team physician Dr. Dan Buss on Friday morning to be re-evaluated.

Thursday was the first time that Neshek has exited a game with the Twins due to an injury, although he didn't pitch after Sept. 16 last season due to a sore right shoulder.

But Neshek acknowledged that this injury concerns him a bit more than the one last year considering that it's the elbow that's hurting.

"I've never had anything like that," Neshek said of the "tweak" he felt in the elbow. "Last year I had a weak shoulder, but I didn't come out of game for it. Hopefully, we'll know more [Friday]."