"It took sheer willpower the other day to get the ball over the other side of the plate toward the end there," May said. "At the beginning it was OK. But as it goes in with the number of pitches, it gets more sore."
May said he first started to feel tightness in his hip in Tampa Bay after his outing on Aug. 25 and that the tightness moved into his back. He pitched in four out of five games after initially feeling the hip tightness, which didn't help the cause. He said rest is the key to helping his injury, but he doesn't have that luxury in the last week of the season.
"The back continues to cause him trouble," Twins manager Paul Molitor said. "It's inhibiting enough that we feel it would be too high risk for him to pitch through it. We're getting down to the last six games here, so I'm not sure how it's going to respond the rest of the week. I'm trying to stay optimistic day to day, but unfortunately there haven't been a lot of days he's been available the last 10 days."
May is clearly frustrated by the injury, as it's coming at an inopportune time with the Twins still in the mix for the second American League Wild Card spot. He's pitched well since being moved to the bullpen, posting a 3.03 ERA with 34 strikeouts in 29 2/3 innings.
"From what I know of Trevor May, this is really eating away at him," Molitor said. "He's enjoyed the role we've given him. We don't know what his future is going to bring. But to take away a chance for him to be contributing is really bothering him. But he's smart enough and the trainers are smart enough not to do something foolish here."
• Saturday's starter against the Royals remains to be determined, according to Molitor, as it'll either be left-hander Tommy Milone or right-hander Phil Hughes. Milone filled in for Hughes in Monday's 4-2 win vs. the Indians, allowing two runs over 5 2/3 innings. Hughes, who was out with flu-like symptoms, said he felt better on Tuesday and played catch without any issues.
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.