The NCAA tournament doesn’t begin until May 31, but there is already an urgent tournament vibe about the rest of South Carolina’s games as the Gamecocks jockey for the right to host one or perhaps two rounds in the tournament.

The 14th-ranked Gamecocks (38-14, 16-10 Southeastern Conference) conclude the regular season at No. 24 Mississippi State (38-15, 14-13) starting tonight. The series has major implications for both teams — not for whether they will make the tournament, because both are already in, but for hosting tournament games.

Baseball America currently has USC hosting one of the 16 regional sites, but not as a lock to host.

Mississippi State is also on the bubble to host, but on the other side of it, trying to play its way in to hosting, according to Baseball America’s projection.

Then there are the top eight national seeds, which guarantee hosting a regional and, if you advance, a super regional — the round before the College World Series in Omaha, Neb.

South Carolina is not currently projected to receive a national seed, but has a chance to earn one. Perfect Game has Oregon and Florida State as the No. 7 and 8 national seeds, with USC, North Carolina State

and Clemson as the three top teams trying to break into the national seed group.

N.C. State has the best credentials of those three — 11-8 against the top 25 of the Ratings Percentage Index (one metric the tournament selection committee uses to pick and slot teams), and 18-10 against the top 50. USC is 4-7 against the top 25 and 10-10 against the top 50. Clemson, which went 1-2 against USC earlier this season, is 8-10 and 17-12.

The rub for USC loyalists is that the Gamecocks want Florida State to slip in this weekend’s final regular season series. But that series is against Clemson in Tallahassee, Fla.

“If Clemson goes to Tallahassee and wins that series, maybe they’re in the national seed mix,” said Baseball America’s Aaron Fitt, who projects the tournament field. “I don’t know that I like Clemson’s resume more than South Carolina’s. But if they go to Tallahassee and win that series, they might leapfrog South Carolina.”

Fitt believes USC could lose regional hosting rights if it is swept at Mississippi State, or goes 1-2 in Starkville and then one-and-done in the SEC tournament.

“If they get swept, they’d need to make a pretty deep run in (the SEC tournament),” Fitt said. “Even if they lose the series, they’ll probably still host. I think the team that wins that (USC-Mississippi State) series will definitely host (a Regional). That’s why I think this series is really interesting. It’s really a swing series for South Carolina.”

That’s because if the Gamecocks sweep Mississippi State, whose home field is one of college baseball’s toughest, they could earn a national seed, especially if they get a quality win or two in the conference tournament.

The way Fitt sees things, it’s possible that the Gamecocks could return from Starkville feeling good about their national seed chances, or wondering if they will even host any NCAA tournament games.

“If they go 2-1 (at Mississippi State), they’ll need some help from other teams (to get a national seed),” Fitt said. “Certainly, I think they could win two or three games in (the SEC tournament) and have a chance. These teams (on the hosting and national seed bubbles) are so tightly bunched together.”

Of USC’s 10 losses, six are to top-ranked Vanderbilt, No. 2 LSU and No. 11 Arkansas. The other four include a sweep at Florida, which is on the fringe of making the NCAA tournament, and a loss at Missouri (16-30, 8-19). Being swept at Florida “stings” USC’s resume, Fitt said, though he does have the Gators among the nine SEC teams projected to make the tournament.

One positive for the Gamecocks: They are playing well at the right time. Since starting 2-4 in league play, they are 14-6 against the SEC. As coach Chad Holbrook expected, they are a better hitting team than last year’s group, batting .286 compared to .265 in 2012.

That’s due in part to sophomore catcher Grayson Greiner and freshman second baseman Max Schrock surging in the second half of this season. Greiner hit .222 overall last year. He now leads USC with a .315 average against league teams. In the first half of this season, he hit .231. In the second half: .360. Schrock hit .212 in the first half and is hitting .370 in the second half.

“This league has a way of preparing you for postseason,” Holbrook said.

A challenge for USC this weekend: Mississippi State has “one of the best closers in college baseball,” Holbrook said. Jonathan Holder has a 1.15 earned-run average, 70 strikeouts and nine walks. And all weekend, Mississippi State fans will ring their cowbells as loud as they have this year, trying to swing this swing series in their team’s favor.

“We’ve got a tall task in front of us,” Holbrook said. “The winner of this series isn’t guaranteed a trip to Omaha. It’s not going to make or break our season, this weekend. Is it big? Yeah. It could put us in a great position. But I’m not going to let this weekend, if it goes south, dictate the rest of our season. We’ve still got a lot to play for. I’m going to try my best to make sure our players keep it in perspective.”