Update: Casey Fien was officially placed on the disabled list Thursday and Michael Tonkin was called up from Class AAA Rochester. The Twins are calling Fien's injury a strained right shoulder.

Righthanded reliever Michael Tonkin is headed to Minnesota and will rejoin the Twins bullpen, likely meaning that Casey Fien, who left Wednesday's game because of soreness in his pitching shoulder, is headed for the disabled list.

Tonkin, who owns a 3.26 ERA in 34 career games with the Twins, has given up two runs in 7 ⅓ innings this season for Class AAA Rochester.

Fien gave up three runs on five hits in Wednesday's 10-7 loss to Detroit at Target Field, including a home run to Miguel Cabrera, before leaving mid-inning because of soreness in his shoulder.

"Casey's shoulder still a little bit tender. We're going to make sure we are on top of that," manager Paul Molitor said. "We're going to get it checked out."

Fien did not want to talk about his condition after the game. He and closer Glen Perkins have been the Twins' most reliable relievers this season, with Fien giving up only two runs in eight appearances until Wednesday.

It was one of three injuries the Twins suffered during the game. Phil Hughes was pulled after five innings, when he volunteered to Molitor and pitching coach Neil Allen that his left hip had begun bothering him a couple of innings earlier, and it was getting worse.

"It was pretty obvious we had to get him out of the game," Molitor said. "He was smart enough to say something."

The "tightness" in Hughes' hip, as he described it, showed up a day after his start Friday in Seattle but went away. After Hughes retired the first eight batters Wednesday, the soreness returned and gradually worsened.

"I'd land on my front foot and I couldn't move after that, it just got locked up. When I said something after the fifth, I couldn't really finish any of my pitches," Hughes said.

Molitor is optimistic that Hughes will be well enough to pitch Monday against Oakland.

One other injury Wednesday appears less serious: Outfielder Jordan Schafer suffered a mild sprain in the MCL of his right knee, but he said he feels fine and anticipates being well enough to play Thursday.

Nolasco decision near

A decision about Ricky Nolasco "is coming together [but] it's not 100 percent yet," Molitor said of this weekend's starting pitching plans. "But I'd like to talk to [General Manager Terry Ryan] before we determine how we want to put it out there."

Nolasco might be in line for a second rehab start, after pitching five strong innings — and throwing only 66 pitches — Sunday at Class A Cedar Rapids. Molitor wouldn't commit to that but did say he has no plans to use a six-man rotation for the moment, mostly because of the strain that going with only six relievers might put on the bullpen, especially since "we're already trying to protect [J.R.] Graham a little bit." The Rule 5 pick hasn't pitched since April 19.

Etc.

• Kennys Vargas returned to the lineup after two days off, albeit in the seventh position for the first time, and produced a pair of singles in four at-bats. "He's done things that we'd hope he'd do during those three days," Molitor said.

• Righthander Kohl Stewart, the Twins' first-round draft pick in 2013, underwent a magnetic resonance imaging exam recently that found no structural damage, Twins director of minor leagues Brad Steil said. The Twins plan to slowly ramp up his workload at Cedar Rapids, Steil said.

• Class AA Chattanooga reliever Adrian Salcedo was suspended for 80 games, Major League Baseball announced, after testing positive for Tamoxifen, a performance-enhancing drug, and Haptaminol, a banned stimulant.