HOUSTON -- Astros left-handed pitcher Kent Emanuel, who threw 8 2/3 innings in relief in his Major League debut on April 24 against the Angels, revealed Thursday he will undergo surgery to fix the ulnar collateral ligament in his left elbow, ending his season.

Emanuel, who turns 29 on Friday, was removed from his May 25 outing against the Dodgers after throwing only four pitches. He had pitched in 10 games this season, all in relief, posting a 2.55 ERA in 17 2/3 innings. Emanuel said he doesn’t yet know if he’ll need another Tommy John surgery.

“We’re hoping it’s a repair, but Tommy John is still on the table,” Emanuel said. “We won’t know for sure until they go in there.”

Emanuel, who underwent Tommy John surgery on June 3, 2015, said he was set to have season-ending surgery Thursday. The procedure is being performed by Dr. Jeffrey Dugas of the Andrews Sports Medicine Center in Birmingham, Ala. He’s the same doctor who performed a “primary repair” procedure on lefty Rich Hill in November 2019.

“Rich Hill’s been the road map for me in this, because he had Tommy John previously and, obviously, he’s had success,” Emanuel said.

Dugas uses tape to form an “internal brace” around the damaged ligament that will allow Emanuel to begin throwing in a couple of months. Emanuel said the recovery time is eight to nine months, which is substantially shorter than Tommy John recovery (12-14 months).

“It’s going to be kind of how it goes because they don’t have a lot of data on it, because it’s so new,” said Emanuel, who tore his UCL at the beginning of 2020 and tried to rehab the injury with platelet-rich plasma and stem cell injections.

The injury is the latest setback for Emanuel, who last year tested positive for dehydrochlormethyltestosterone in violation of MLB’s Joint Drug Prevention and Treatment Program and was suspended for 80 games. Emanuel vehemently denied “knowingly or intentionally” taking the substance, saying last year he didn’t know how 7 picograms of the long-term metabolite of DHCMT got into his system.

Emanuel was called up in April shortly after his suspension ended and wore jersey No. 0, which he said is how many games he should have been suspended.

On April 24, Astros pitcher Jake Odorizzi left his start against the Angels after one out because of an injury, and Emanuel took over. He became the first reliever to throw 8 2/3 innings since the Yankees’ Neil Allen on May 31, 1988, at Oakland. It was the longest relief outing by an Astros pitcher since Mike Cosgrove (8 2/3 innings) on June 18, 1974.