MINNEAPOLIS — Twins top pitching prospect Kyle Gibson was diagnosed with a flexor pronator muscle strain of the right elbow and a partial tear of the ulnar collateral ligament, and will head to Fort Myers, Fla. this week to begin strengthening and flexibility exercises of the right shoulder and elbow, according to general manager Bill Smith.

Gibson is expected to avoid Tommy John surgery for now, as the estimated return for him will be determined after the initial phase of his rehab program.

Fellow Triple-A Rochester right-hander Anthony Slama was also diagnosed with a flexor pronator muscle strain of the right elbow, and will head to Florida to begin his rehab process along with Gibson.

Both pitchers underwent MRIs last week and met with team orthopedists, Dr. Dan Buss and Dr. John Steubs, on Monday, before undergoing further testing on Tuesday.

Gibson, 23, was originally placed on the Minor League disabled list with soreness in the flexor muscle area near his elbow and underwent an MRI on Wednesday. The 6-foot-5 right-hander is the 33rd-ranked prospect in baseball and No. 2 in the Twins’ system, according to MLB.com.

Gibson, the club’s first-round pick in the 2009 First-Year Player Draft, had been struggling recently, as he went 0-5 with a 6.47 ERA in eight starts over June and July. It came after he entered June with a 3.60 ERA and 59 strikeouts in 55 innings.

Slama, meanwhile, was placed on the Minor League disabled list on July 6 because of elbow soreness. The reliever posted a 2.92 ERA with 42 strikeouts in 37 innings with Triple-A Rochester before his injury. The 26-year-old also tossed 2 1/3 scoreless innings with the Twins this year in a brief stint with the club from late May into early June.

ANAHEIM — Twins top prospect Kyle Gibson was placed on the Minor League disabled list with a right flexor mass and underwent an MRI today, and is expected to receive the results on Monday.

Gibson, who is expected to fly to Minneapolis on Sunday, will have the results of his MRI examined by team physicians Dr. John Steubs and Dr. Daniel Buss tomorrow. The Twins are worried the 23-year-old could need Tommy John surgery.

Gibson, a 6-foot-6 right-hander who was the club’s first-round Draft pick in 2009, had his start with Triple-A Rochester skipped on July 27 after experiencing soreness near his elbow. He has a 3-8 record and a 4.81 ERA in 18 starts this season, with 91 strikeouts and 27 walks over 95 1/3 innings.

“You’re always concerned it might be the ulnar nerve,” Twins Minor League director Jim Rantz said by telephone. “I think we’ve got to wait until we get a reading from our doctors. But there’s enough concern that we’re bringing him to Minnesota.”

Fellow Rochester right-hander Anthony Slama, who was placed on the Minor League disabled list on July 6, is also scheduled to head to Minneapolis for tests on his elbow.

“He’s been out a while and doesn’t seem to be getting any better,” Rantz said.