COLUMBIA — The most important thing that happened Tuesday at Carolina Stadium had nothing to do with South Carolina’s 9-5 over Charleston Southern.

Certainly, the 8,114 fans who showed up for the game could take some things out of it — primarily that senior pitcher Colby Holmes continues to be a shell of his former self, which is significantly hamstringing coach Chad Holbrook’s options.

But the biggest development for USC (23-6) on Tuesday happened before the game, when ace left-hander Jordan Montgomery threw a bullpen session as he continues to recover from an elbow bone stress reaction. Holbrook felt encouraged by Montgomery’s bullpen session Friday, and Montgomery was given the go-ahead to throw again this week.

Holbrook doesn’t want to speak in absolutes just yet, but Montgomery’s work Tuesday clearly moved him one step closer to returning. Montgomery has already missed more starts this season (four) than he has made (three), but he was masterful in those three — a 0.95 ERA, 19 strikeouts, seven walks and a .188 opposing batting average.

After Tuesday’s game, Holbrook described Montgomery’s bullpen session as “fantastic” and said, “He pitched completely pain free. He is excited about throwing this weekend. With that being said, if he’s sore (Wednesday), we’ll re-evaluate. As we leave here, all systems are a go for Jordan.”

Holbrook later said the “all systems go” line might have been a bit strong. But at this point, there is a very real chance that Montgomery starts Sunday at Tennessee. Holbrook will start Nolan Belcher, his best pitcher to date, on Friday, and almost certainly will go with Evan Beal on Saturday. If Montgomery does start Sunday, he will be on a “very conservative” pitch count, Holbrook said. He estimated that means probably 70 to 75 pitches at the most.

Whenever Montgomery pitches again, Holbrook said he will definitely start.

Beal, a right-hander, was a strong setup reliever before Montgomery’s injury, and formed a formidable tandem with lefty closer Tyler Webb, who has a 0.84 ERA, 32 strikeouts and six walks in 15 appearances this season, with 11 saves. (Holbrook wants to rest Webb and Adam Westmoreland for tonight’s game at Furman).

Ideally, Montgomery’s return would mean Beal becomes a reliever again. But Holbrook said that between Beal “learning how to be a starter” and Holmes sputtering, “I don’t know if we’re in a position to be able to do that yet.”

Charleston Southern (11-17) had 13 hits Tuesday, which tied the most allowed by USC this season. Yet all but the four that came against Holmes were off pitchers unlikely to offer major contributions in SEC games.

Holmes allowed two runs and threw 43 pitches in 31/3 innings — a limited outing that will allow him to be a relief option at Tennessee. But he failed Tuesday to build on last week’s gem at College of Charleston (four hits and a run in 71/3 innings). A weekend starter the past two seasons, he seemed to have most past the three ugly starts that preceded the Charleston game. Then came Tuesday’s issues, and more difficult pitching decisions for Holbrook.

“I thought Colby was just OK,” Holbrook said. “That’s not the Colby that’s pitched at a high level for us. Colby’s been around the block a time or two. With that being said, he’s got to pitch better than he’s pitched.”