The Twins aren’t ready yet to fill Kyle Gibson’s spot in the starting rotation. It’s possible they might have two spots.

General Manager Terry Ryan is in Rochester, N.Y., the team said, and will confer with manager Ron Gardenhire and his staff before they decide who faces the Indians in Cleveland on Saturday. That would have been Gibson’s day to start, but the rookie righthander was optioned to the Class AAA Red Wings after Minnesota’s 6-1 loss to the Mets.

But who starts Friday’s game is in question now, too. Righthander Samuel Deduno has been diagnosed, assistant general manager Rob Antony said, with biceps tendinitis, a fancy way of saying his pitching arm is sore.

Deduno “came into the training room after pitching [Sunday] and said he was a little more sore” than usual, Antony said. Deduno reported some irritation in his upper arm and shoulder that was preventing him from throwing his pitches at full speed, so the Twins are being careful about working him between starts this week. “Right now we would not rule out him making his next start on Friday,” Antony said, “but that’s subject to change.”

The Twins hope Deduno’s problem is simply the strain of pitching for six months, particularly since he also took part in the World Baseball Classic in March.

“Any time a pitcher comes to you, you have to take that seriously and follow up on it. Sometimes, two days later they throw and say, ‘It doesn’t feel like it did. I think I’m OK,’ ” Antony said. “Come Wednesday, if it’s not better, if he goes and plays catch and still feels [sore], there a chance” Deduno would have to go on the disabled list.

“Maybe he’s got a little arm fatigue,” Antony said. “It’s not uncommon this time of year for a pitcher to throw through that.”

Deduno is 7-7 with a 3.82 ERA this year, but he’s given up 13 earned runs in 16⅔ innings in his past three starts, a 7.02 ERA.

Starter candidates

The Twins have a couple of pitchers with major league experience in Rochester, with P.J. Walters and Scott Diamond available for a call-up if necessary (although Walters would have to be restored to the 40-man roster).

“Terry’s going to look at a few people,” Gardenhire said. “We’re not ready to make a decision.”

The manager mentioned one candidate, however, someone he’s discussed before — and someone who auditioned well for the job once more on Monday. Long reliever Anthony Swarzak allowed one run on three hits over three innings against the Mets, continuing his strong work in that role.

“He’s done really well where he’s at, but that’s not to say we won’t put him in there,” Gardenhire said. “He’s a candidate.”

Gardenhire’s reluctance to shift Swarzak is understandable; he seems to be at his best when the Twins need him most. Monday was the sixth time this season Swarzak has entered a game in the fourth inning or earlier, and he’s posted a 2.53 ERA in those situations, striking out 20 while walking only three in 21⅓ innings.

“He eats up innings; he’s got arm strength, where he can get us through three or four innings and keep you in the ballgame,” Gardenhire said. “That’s why he’s so valuable there. … If we moved him, we’d have to fill that hole.”