Trevor May's season remains a mystery. On Friday, the Twins gave their 26-year-old reliever a couple of weeks to solve it.

May missed a week earlier this month because of back spasms, a problem that seemed to disappear after the righthander was administered a cortisone shot on Monday. He told manager Paul Molitor on Wednesday that he felt completely recovered. And then on Thursday, he pitched.

"It didn't seem right. When you watch his pitches and the lack of efficiency — it wasn't so much that the numbers were down, it's just that he couldn't get it where he wanted to," Molitor said of May's three-batter, three-run calamity against the Marlins. "It's a little bit puzzling in how we're going to figure it out, because some of the pain issues have subsided."

Five weeks into the season, May appeared primed for a great season as a setup man in the Twins bullpen. He struck out 27 batters in his first 19 innings, and had an ERA of 1.89. Since then? He's pitched in only 12 games, and only for a total of 7 ⅔ innings. His ERA in that span? An alarming 16.43.

The Twins placed May on the 15-day disabled list Friday, mostly to buy time.

"Whether it's a flexibility issue, whatever it is, he can't get his body in position. They're going to look at some film and try to compare to see if there's anything different," Molitor said. "He feels better. He just's kind of puzzled why his body's not working right. We're going to give him a chance to work it out."

The Twins believe it's nothing serious. "He's got experience with these back spasms. We thought we had it under control," General Manager Terry Ryan said. "Not quite. Hopefully it will take care of itself over 15 days. We thought he was OK."

Hughes shelved, too

Phil Hughes underwent an magnetic resonance imaging exam Friday on his left knee, but the Twins took no chances. They placed him on the disabled list earlier in the day, and activated Kyle Gibson from the DL. Gibson will start Saturday.

Hughes left the ballpark on crutches Thursday night after being struck on the knee by a line drive from Miami's J.T. Realmuto. X-rays found no break, but Ryan said "the right thing to do is get an MRI and make sure there isn't anything cracked in there."

"I know he's disheartened," Molitor said of Hughes, whose 5.95 ERA had caused the manager to move him out of the rotation. "He said something last night like, 'Par for the course.' "

Step backwards?

Closer Glen Perkins threw another bullpen session, which had been expected to be the final step before the Twins considered sending him on a rehab assignment.

But Molitor hinted after Friday's game that it didn't go well and that the plans had changed, though he did not elaborate.

"I don't think it was a great day for him in terms of progress," Molitor said. "We're going to reconsider where he's at."

Perkins has not pitched since April 10 after suffering a strain in his pitching shoulder.

Chargois on his way

The Twins called up J.T. Chargois from Class AAA Rochester, hoping he can stabilize a bullpen that seems to change personnel every week.

Thanks to some travel difficulties, the righthander did not arrive for Friday's game. But Molitor plans to limit his work, much as his minor league teams have done. Chargois missed the 2013 and '14 seasons after Tommy John elbow surgery, and now that he's throwing 98 mph-plus again, the Twins plan to be careful.

"Hopefully he can find his way and start working his way up that bullpen ladder," Molitor said.

He certainly did in Chattanooga and Rochester, where the 25-year-old gave up only 14 hits in 24 innings this season, while striking out 34.