The addition of outfielder Ryan LaMarre gives the Twins 13 position players and 12 pitchers, a roster mix they haven’t carried since the beginning of the season.

Most teams carry 13 pitchers, and this arrangement is not expected to last long. In fact, it might not last past Thursday’s scheduled off day before the Twins open a three-game road trip at Seattle this weekend. Expect the Twins to light up the transaction wire between the end of Wednesday’s series finale against Detroit and Friday’s game at Safeco Field.

“Things can be a little bit volatile in terms of the roster,” Twins manager Paul Molitor said, “but, in the short term, getting Ryan up here seemed to make a lot of sense.”

Molitor explained that Jose Berrios pitching eight innings in Monday’s 4-2 victory over the Tigers saved the bullpen and allows them to carry one fewer reliever for a couple games. So LaMarre received an 11 p.m. call Monday to head to the Twin Cities. He hopped on a plane from Lehigh Valley (Penn.) International Airport around 6:30 a.m., changed planes in Detroit and was in Tuesday’s starting lineup as the right fielder.

The Twins also are in a stretch in which they are facing several lefthanded starters — Seattle ace James Paxton is waiting for them Friday — and LaMarre’s righthanded stick can help balance out the batting order.

“We thought that with [Berrios’] long start, our pen would be OK with seven [relievers] for the next couple of days,” Molitor said, “and, maybe, coming off of the off day, we are going to have some moves to make.”

In an ideal world, the Twins would give Miguel Sano more time to get his bat sharp during his minor league rehabilitation assignment at Class AAA Rochester, but he could return and be activated in time for the Seattle series. He’s scheduled to play nine innings at third base Wednesday for the Red Wings.

Starter Trevor May pitched against Lehigh Valley on Tuesday and is scheduled to pitch Sunday, where he will go six innings or 90 pitches. But the Twins might call up a reliever — Alan Busenitz is a possibility.

Santana schedule

Ervin Santana’s outing in Fort Myers was rained out Monday, so he headed for Class AA Chattanooga to pitch Wednesday. That will start the 30-day clock on his minor league rehabilitation stint.

“I don’t know how much of a difference it is going to make in the long run,” Molitor said of the delay. “Maybe how he gets slotted in when he is ready, a day or a game or something like that. I’m not sure how much we are going to want him to pitch before we feel he’s ready as far as outings down there. We will see how it goes.”

After Santana pitches, he’ll return to Fort Myers, Fla., for some extra work, then make his next start for Class AAA Rochester on Monday.

Could Santana be activated after only two minor league rehab starts?

“Only if we were pretty high in need,” Molitor said.

Mauer update

Molitor said first baseman Joe Mauer made some progress as he recovers from a cervical strain and the concussion symptoms that came with it.

“Joe was here [Tuesday],” Molitor said. “The neck is showing a little bit of response to treatment, as far as the tenderness. And some of the other [symptoms] … seem to be lessening to some degree, so that’s encouraging.”

Etc.

• Shortstop Nick Gordon was promoted to Class AAA Rochester after batting .333 with five home runs and 20 RBI in 42 games for Class AA Chattanooga.

• The Twins acquired slugger Chris Carter from the Angels for cash. Carter has been in Class AAA Salt Lake, where he batted .255 with 13 homers and 43 RBI in 38 games. He will be assigned to Class AAA Rochester.