The room is not far from Carolina Stadium’s field, but it felt like a world away. Almost every day during the 2011 season, South Carolina pitcher Nolan Belcher walked in and steeled himself for another round of rehabilitation exercises after Tommy John surgery.

This was going to make him better in the long run. He knew that. He knew pitchers often return stronger than ever from the now-common elbow surgery, during which the damaged ulnar collateral ligament is replaced with a tendon from elsewhere in the body. In the 1980s, Tommy John surgery was “maybe a death sentence for a pitcher,” said USC coach Chad Holbrook. The recovery rate isn’t 100 percent, but nobody views it that morbidly anymore.

Still, this did not make Belcher’s rehab any less agonizing.

Immediately after Tommy John surgery, the arm is in a cast, bent at almost a 90-degree angle. The first step to snapping off curveballs again is reestablishing range of motion. For Belcher, this meant rehab sessions with a band wrapped around his scarred left arm, and a weight hanging off the band, to stretch his arm straight and hold it there.

“That’s excruciating pain,” he said. “It almost hurts as much as when you first tear the ligament. Physically, that was the toughest. None of it compared to just how mentally, what a strain it is, going in there every day, knowing that you can’t play and you’re watching your teammates out there having fun and doing well. And you just wish you could join them. It’s a lonely feeling.”

The 2011 season was going to be Belcher’s third at USC. After a freshman year, 2009, during which he started on the weekend, his junior year set up as a chance to impress Major League scouts and get drafted. That it didn’t unfold as expected matters little now, because Belcher has been one of college baseball’s most surprising stars this season.

He began as the Sunday starter, after starting six games in 2010 and two in 2012. Before the season, he said his arm recovered quicker than ever after throwing. His coaches felt optimistic that he was confident again, after overcoming doubts about his elbow last season, when he had a 2.12 ERA in 292/3 innings — the same number he threw in 2010.

But nobody could have imagined Belcher would perform like this. Through 10 starts entering tonight’s game at second-ranked LSU, Belcher has a 1.70 ERA in 74 innings, with 61 strikeouts and five walks. He has thrown at least seven innings in eight straight starts. From late February to late March, he did not walk a batter in six straight starts, and struck out 42. Even with Jordan Montgomery now back from an elbow injury that sidelined him for four starts, Belcher has remained the Friday starter.

“I’d be lying if I said I was expecting this,” he said.

He is doing this because he knows what to expect from a sometimes-unpredictable pitch — the curveball. He uses it more early in the count, because he can locate it, and because he knows most hitters will not swing at a curve when it is the first or second pitch of an at-bat.

USC catcher Grayson Greiner said most hitters expect Belcher to lean on his fastball and changeup, based on scouting reports. When Belcher hooks a curve on the first pitch or even when he is behind in the count, “it kind of freezes” batters, Greiner said.

Even after his strong freshman season, Belcher never banked on playing professional baseball. He is 5-8 and 155 pounds, and looks nothing like the lanky lefties with slingshot arms who have high draft value. His success in spite of his stature earns respect from teammates.

“Most people would look at him and wouldn’t expect it,” said Montgomery, a 6-4 lefty. “I like that.”

For all Belcher learned while majoring in sports management, which he hopes to parlay into an administrative job in a college athletic department, the brutal rehab after surgery provided an equally valuable less in perspective.

“I wouldn’t change it,” Belcher said. “I’d still go through it again if I had the chance. It makes you tougher. It makes you realize that nothing can really slow you up. It doesn’t get much worse than that.”