Buddy Boshers made a big mistake Sunday: He pitched.

The lefthanded reliever became a casualty of the Twins’ sudden shortage of bullpen arms and surplus of bullpen innings, spending roughly six hours in the big leagues before being sent back to the minors.

“It’s not an easy conversation,” manager Paul Molitor said of his hello-goodbye with Boshers, “when a guy comes up and does his job.” Boshers did his, bailing out the Twins, after Kyle Gibson recorded only eight outs, by retiring seven of the eight Tigers hitters he faced in a 13-4 loss. But by pitching those 2⅓ innings, Boshers sealed his fate, because the Twins bullpen is still overworked, and he couldn’t pitch for another few days.

The solution? Return Boshers to Class AAA Rochester, and summon Nick Tepesch, whose arm is fresh. Tepesch, a former Rangers righthander whose ERA was 2.00 with the Red Wings, will meet the Twins in Texas on Monday. Lefthander Ryan O’Rourke, sidelined for a month by an elbow strain, is expected to be transferred to the 60-day disabled list, making room for Tepesch on the 40-man roster.

Had Gibson pitched a few more innings, Boshers could have remained with the Twins, at least until their pitching crunch, fueled by giving up 40 runs in five games, eased up. Instead, he’s a victim of the same circumstance that led to his promotion in the first place; after Saturday’s blowout loss, the Twins decided to give Justin Haley’s bicep tendinitis 10 days to convalesce, in order to add Boshers’ low-mileage arm.

Boshers was realistic about his status as a disposable arm. “That’s a benefit of being on the 40-man roster,” he said with a shrug. “When they need you, they need you.”

Now they need Tepesch, who obviously won’t mind. He has struck out 17 batters in his 18 Class AAA innings this year.

Vargas back up

Kennys Vargas also joined the Twins on Sunday, temporarily giving the Twins a four-man bench. The 26-year-old first baseman admitted that his 18-day stint at the World Baseball Classic with Team Puerto Rico cost him a chance to start the season with the Twins.

“To be honest, I didn’t take that many at-bats during spring training, even during the Classic, so I understand the decision they made,” Vargas said. “I just keep my mind positive and go down and keep working every day. I said, ‘Any moment, I get the call.’ ”

The switch hitter will pinch-hit and back up Joe Mauer, which means fewer innings, if any, at first for Miguel Sano. “I kind of like him at third right now,” Molitor said of Sano, who has started twice at first base.

Etc.

With off days scheduled for Thursday and the following Monday, the Twins, having demoted Adalberto Mejia after Saturday’s loss, will revert to a four-man rotation until May 6 against Boston. Molitor said he and the front office are in no hurry to decide who gets that start.

• A day after a bench-clearing shoving match broke out, there were no further incidents between the teams Sunday. “I think it’s over,” Molitor said of the dust-up, which resulted in Sano and Detroit pitcher Matt Boyd being ejected.

• Twins catcher Chris Gimenez retired Andrew Romine on a fly out to end the ninth inning. Gimenez, who pitched once for the Rangers in 2014 and twice for the Indians last season, threw four “heaters,” as he called them, three of them slower than 70 miles per hour, to retire Romine, and reduced his career ERA from 9.00 to 8.31.