LOS ANGELES -- Dodgers right-hander Tony Gonsolin already was lost for the remainder of this season. Now his absence is expected to extend through the end of the 2024, as well.

The Dodgers on Monday announced that Gonsolin will need Tommy John surgery. The procedure is set for Friday and will be performed by team doctor Neal ElAttrache.

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“We knew he was dealing with elbow issues but there was a point where he felt he could pitch and get Major League hitters out ... until he couldn’t,” Dodgers manager Dave Roberts said. “Talking to the doctors, we felt it was time to do, I guess, what was at some point inevitable.”

Gonsolin, 29, was placed on the injured list Aug. 19 with what was diagnosed as right forearm inflammation. He also was placed on the injured list late last season with a right forearm strain. He started this season on the IL with a left ankle sprain and had a rocky ride in 2023.

Gonsolin was 8-5 with a 4.98 ERA in 20 starts and had been dealing with arm soreness for an extended period before he went on the IL. Roberts was asked if continued use through the discomfort directly led to the need for surgery.

“He felt like he could keep pitching, and, to be quite honest, he could still pitch right now,” Roberts said. “But it just wasn’t productive. With all pitchers, I’m assuming that there’s always some damage or tears. Some guys can pitch through it, which Tony did.

“There is nothing that an MRI showed after his last start that was worse, which caused the Tommy John. This is something that he had on his mind. We thought [Tommy John surgery] was a potential [outcome] from the middle of the season.”

Gonsolin’s last outing was the worst of his career. He gave up 10 runs on eight hits and four walks in 3 1/3 innings Aug. 18 against the Marlins.

Gonsolin earned $500,000 bonuses for making 14, 16, 18 and 20 starts this season and was in line for additional $500,000 bonuses for his 24th and 28th starts.

“I think that was motivation to pitch,” Roberts said. “I can sympathize and understand that, from a player’s perspective. And I still believe that if we would have stopped this process months ago, he would be in the same position to have Tommy John surgery. It was one of those things where we had a real honest conversation with Tony.”

Gonsolin was named to his first National League All-Star team last season after going 11-0 in the first half with a 2.02 ERA in 17 starts. He finished last season 16-1 with a 2.14 ERA in 24 starts and a career-high 130 1/3 innings.

Right-hander Ryan Pepiot appears to be in line to step into the starting rotation down the stretch, with fellow righty Gavin Stone making a case to be included. Stone went six strong innings as a bulk reliever against the Red Sox on Sunday.

Pepiot appeared set to start the season in the Dodgers’ rotation because of Gonsolin’s sprained ankle before landing on the IL himself with an oblique injury. Pepiot returned to the mound in July and came back to the Dodgers earlier this month, posting a 2.00 ERA in two relief outings (nine innings).

Pepiot was returned to Triple-A Oklahoma City on Friday but could be set to return soon. Stone was sent down Monday when right-hander Tyson Miller was added to the active roster.