ST. LOUIS -- The bad news continued for the Marlins on Thursday morning in a young season off to a tough start.

Marlins right-hander Eury Pérez will undergo Tommy John surgery with an internal brace on Monday and miss the rest of the 2024 season, president of baseball operations Peter Bendix announced on Thursday. The determination that surgery was necessary came after Pérez visited Dr. Keith Meister for the second time in less than two weeks after experiencing tightness in his elbow during his bullpen session on Tuesday.

“It’s been a bit of a roller coaster,” Bendix said. “Initially having the frustration of the elbow soreness and followed by the positive outlook on [thinking] you don’t need surgery right now. There was an understanding that the ligament was not in great shape and essentially, you can pitch with it until you can’t, and nobody knows when that’s going to be. You have to try and see when the symptoms return. And unfortunately, that happened now. Better now than in the middle of the season.”

The 20-year-old Pérez first experienced right elbow soreness on March 14 and alerted the training team after exiting his Grapefruit League outing the day before due to discomfort from a broken nail on his right middle finger. His four-seam velocity had dipped from above 98 mph to 95.1 mph on his final offering.

When Pérez first traveled to Texas to see the specialist last month, testing revealed mild right elbow inflammation and no structural damage. Pérez then began playing catch a couple days later, on March 23, per the recommendation of Meister, and had been scheduled to progress to throwing a bullpen session this week.

“Essentially, the idea is if the elbow doesn’t hurt, you keep pitching and you build up,” Bendix said. “At some point, the elbow’s going to start hurting again. It might be in two weeks. It might be in two years. You can’t find out until you build up.”

Instead, the Marlins have now lost Pérez for all of 2024 and some of the '25 season (the timeline for Tommy John surgery rehab ranges from 12-18 months). It’s a significant setback for a club that is winless through its first seven games, in large part because its starters entered Thursday's series opener in St Louis averaging just 4 1/3 innings, walking the most batters (21) and ranking toward the bottom in starters' ERA (5.93).

There was some encouraging news on the injury front, as right-hander Edward Cabrera (right shoulder impingement) and left-hander Braxton Garrett (left shoulder impingement) are two rehab starts away from returning.

Last year in his rookie season, which was cut short by left SI joint inflammation, Pérez lived up to the hype as one of baseball's top pitching prospects. In 19 starts, he posted a 142 ERA+ and a 1.13 WHIP, striking out 108 batters in 91 1/3 frames.

Pérez's mentor, Marlins ace Sandy Alcantara, underwent Tommy John surgery in early October. He began his throwing progression on March 9.

“It’s obviously horrible for us, but it’s horrible for him,” Marlins manager Skip Schumaker said. “That poor kid tried as best as he could to come back and be part of the 2024 team. He was going to be one of our aces, if not the ace replacing Sandy this year, [along] with [Jesús] Luzardo, obviously.

"It definitely hits. I’m not going to sugarcoat it. It’s not easy to hear one of your best pitchers going down again, but I feel confident that he’ll come back. Him and Sandy will be together in the dugout all the way through. I’m not happy that he’s sitting in the dugout next to Sandy, but it’s kind of where we’re at and an opportunity for someone to step up.”