HOUSTON -- The Astros will be without veteran right-hander Lance McCullers Jr. for the remainder of the regular season after he underwent surgery Tuesday to repair the flexor tendon in his right forearm and remove a “lima bean”-sized bone spur that had been causing some pain in the arm.

The news wasn’t a surprise considering McCullers had a setback last month during his rehab and had stopped throwing. The team said last week he was set to undergo an MRI on Friday, which led McCullers to a second operation on his right arm. He missed the entire 2019 season after Tommy John surgery.

“In talking with Lance, he’s feeling a lot better right now about things in his future,” Astros General Manager Dana Brown said Wednesday.

Brown said McCullers won’t resume throwing until November. He didn’t provide a timetable on his return beyond that, except to say he won’t pitch until sometime in the 2024 season. Brown said McCullers’ ulnar collateral ligament remains in good shape.

“You hate seeing anybody hurt, especially hurt a second time,” Astros manager Dusty Baker said. “From what I’ve talked to the trainers and the doctors, he has a chance to be back as good as new. If anybody can come back, it’s Lance because he’s in great shape and works his butt off. I’m sure it’s a little bit of a downer, but he knew something was wrong.”

McCullers is the second Astros starting pitcher to be lost for the season after Luis Garcia underwent Tommy John surgery on May 19.

The Astros, who also lost starter José Urquidy to right shoulder inflammation in early May, have continued to pitch well despite being down three starters. Rookie Hunter Brown has excelled in McCullers’ spot to start the year, and Brandon Bielak and J.P. France have held their own after being brought up from Triple-A. Houston entered Wednesday with the best ERA in baseball (3.28).

Brown said the Astros are in good shape in terms of pitching depth and said the club will likely be in the market for another bat at the Trade Deadline more so than another arm.

“Our young guys are stepping up right now and we’re expecting them to gain some more experience,” he said. “It’s going to give our young pitchers an opportunity to step it up, and adding guys like [Ronel] Blanco to the rotation is going to be helpful. At some point [next year] we’re going to get McCullers back, and the beauty of it is we feel like we’re going to get a completely healthy McCullers that could post throughout the rest of this time.”

McCullers injured the tendon during Game 4 of the 2021 ALDS and chose rest and rehab. He made only eight starts in the regular season at the end of last year, going 4-2 with a 2.27 ERA, and started three games in the postseason.

When he reported to Spring Training, McCullers aggravated the injury while throwing in the bullpen on Feb. 14 and was still hopeful he could pitch 180 innings. His rehab had progressed early last month to throwing 35 pitches off a mound, hitting 93 mph, before he felt the same pain he experienced in February.

“Lance is a grinder, and he tried, with pure grit, to fight through the injury and come back,” Brown said. “Starting out this year, he felt he was going to be fine and continued to press through it and it continued to bother him. With this surgery, we feel good because at the end of the day it was just the flexor tendon and bone spur, which gives him a chance to come back in ‘24. Right now, it’s a little early to tell how soon he’s going to come back.”