Casey Fien was back in the Twins bullpen Friday, his shoulder healed and his fears allayed.

“When you get that [magnetic resonance imaging test], you never know what it’s going to show, so that’s what scared me the most,” the 31-year-old righthander said. “But when the MRI came back and showed a healthy shoulder, we knew it was muscle, and it would just take some time to throw pain-free.”

It took about three weeks, plus another spent on a rehab assignment with Class AAA Rochester. Fien was activated Friday, though he understands his setup role in front of closer Glen Perkins belongs to Blaine Boyer, at least for the moment.

“I would imagine at least in the short term, if we get in a situation late … Casey would probably precede Boyer into the game,” more likely the seventh inning than the eighth, manager Paul Molitor said. “That could change; we’ll see how Casey’s doing. But for now, I’m comfortable with Boyer out there, getting outs in the eighth inning.”

That’s OK with him, Fien said.

“Roles don’t really matter. It’s about getting outs,” he said. “And sometimes those outs in the seventh inning are the biggest ones in the game. So I’ll be ready.”

Tonkin optioned down to Rochester

To make room for Fien, the Twins optioned righthander Michael Tonkin to Rochester, though Molitor emphasized that “it’s not a matter of him doing anything wrong. It’s just a matter of how it fits right now.”

Tonkin pitched in 11 games and posted a 5.14 ERA since being called up to replace Fien four weeks ago, but he had held the opposition scoreless in five of his past six outings. He struck out seven and walked two in his seven total innings and allowed only three of 13 inherited runners to score.

“All the outings weren’t great,” Molitor said. “But when you think about games we won over the past 2-3 weeks, there’s been a lot of times he’s gotten really big outs. I let him know we saw that. I know he’s a guy that can help us up here.”

But the team decided to send him out, rather than Ryan Pressly or Tim Stauffer, because Tonkin is considered more of a one-inning pitcher.

“Pressly might have more ability to go long,” General Manager Terry Ryan said.

And the team still intends to reduce its bullpen to seven pitchers again, instead of the eight the Twins are carrying now.

“Obviously he’s disappointed, and rightfully so,” Molitor said. “Like we tell everybody, ‘Don’t get down, keep doing what you’re doing. Things change in a hurry, and you never know how fast you might be back up here.’ ”

Colabello on a tear

If anything, Chris Colabello is hotter to open this season than he was last year. He batted .346 with three homers and 26 RBI in the Twins’ first 20 games last season, and was becoming such a folk hero, the Twins arranged a “Colabello Cowbell” giveaway night.

Colabello, claimed off waivers by the Blue Jays last winter, started this season in Class AAA, but he’s been feasting on major-league pitching again since being called up earlier this month.

Entering Friday, the former International League MVP is batting .386 for the Blue Jays, with three homers and 12 RBI.

Does this streak feel like that one?

“I don’t like calling it a streak. It’s going about my business every day,” Colabello said. “Same with [last] April — I was going about my business. My goal isn’t to have three hits, it’s to have competitive at-bats. It gives you the freedom to just go out and play, and if they go through, they go through.”

Calabello is one of four former Twins playing for Toronto, though he’s the most recent. Pitchers R.A. Dickey and Liam Hendriks and infielder Danny Valencia are also on the roster.

Sano out again

Chattanooga third baseman Miguel Sano missed his second straight game Friday because of a jammed index finger. The injury is not considered serious, Ryan said, and he should be back in the lineup this weekend.