COLUMBIA — Before South Carolina traveled to Mississippi State for last weekend’s regular season finale series, Gamecocks coach Chad Holbrook sounded convinced when he said he believed his team had done enough to host an NCAA tournament regional, regardless of what happened from there on out.

Maybe Holbrook was indeed completely convinced. Certainly, he is more than a little biased. But it is clear now that USC hadn’t done enough then, and perhaps still hasn’t, to lock up one of the 16 regional hosting sites. To be sure, the Gamecocks could end up hosting. Yet their position continues to get shakier, and they can only wait and watch it all unfold.

The Gamecocks went 1-2 at Mississippi State, but were in good position to host because Arkansas closed the regular season by going 1-2 at Auburn.

USC headed to this week’s Southeastern Conference tournament needing two things not to happen. First, USC couldn’t afford to go 0-2 and head home. Second, the Gamecocks couldn’t afford to see Arkansas make a deep, resume-building run.

But USC did go 0-2, losing to Mississippi State on Wednesday and Vanderbilt on Thursday. And Arkansas has started 2-0, with wins over Mississippi and LSU.

The latter is significant because LSU is No. 6 in the Ratings Percentage Index, one metric the NCAA tournament selection committee uses to arrange its 64-team field.

Arkansas’ win over LSU boosted the Razorbacks from No. 45 to 31 in the RPI. LSU beat Alabama on Friday, setting up a rematch with Arkansas — and a potentially resume-building win for the Razorbacks — in today’s single-elimination semifinals.

Beating LSU might not boost Arkansas into USC’s area of the RPI — the Gamecocks were No. 12 as of Friday — but it clearly wouldn’t help USC. The Gamecocks were swept by Arkansas in the regular season and went 17-15 against the top 100 of the RPI, including 11-14 against the top 50. Arkansas is 17-16 against the top 100 and 17-15 against the top 50, but has two losses to teams rated higher than 200.

Aaron Fitt, who projects the NCAA tournament field for Baseball America, noted that it would not be unprecedented for a team in the 30s of the RPI to steal a regional hosting spot from a team in the teens — which could happen with Arkansas and South Carolina. In 2011, UCLA was No. 34 in the RPI and hosted over No. 14 Arkansas.

This year’s Razorbacks have the credentials to reverse those fortunes. They finished third in the SEC regular season, going 18-11 in the league, compared to USC’s 17-12.

Kendall Rogers of Perfect Game believes Arkansas hasn’t done enough yet to overtake USC. Though he still projects the Gamecocks to host, another Arkansas win today could help turn the tide.

Based on Fitt’s RPI analysis and Friday’s results, there are four teams competing for the final two regional hosting spots: USC, Clemson, Arkansas and Virginia Tech. Friday’s RPI had Virginia Tech 11th, USC 12th and Clemson 13th.

USC has an advantage over Clemson because the Gamecocks went 2-1 against the Tigers during the regular season.

Virginia Tech, one of the country’s hottest teams, is making a late charge for a regional host site. The Hokies are not a perennial power, but they made the NCAA tournament in 2010 and came to Columbia for a Regional. The Gamecocks went 3-0 in that Regional, beating Virginia Tech in the final game, en route to their first national title.

The Hokies have won 16 of their past 18 games. In the ACC tournament, they beat Virginia (No. 3 RPI), Florida State (No. 9) and Georgia Tech (No. 22) to make Sunday’s final. The Hokies are now 23-15 against the RPI top 100 and 13-14 against the top 50 — better numbers than USC’s.

At this point, USC needs Virginia Tech to lose the ACC final and Arkansas to lose today to LSU.

The regional host sites will be announced Sunday night. The rest of the tournament field will be revealed Monday.

The Gamecocks want to play as many home games as possible. They are 55-8 all-time in tournament home games, with 24 straight wins, and 35-31 on the road. USC last traveled for a regional in 2008 and 2009. It lost those regionals, at North Carolina State and East Carolina.

Of course, Holbrook isn’t going to worry much between now and Sunday night about RPI or the tournament fortunes of past USC teams. He knows the Gamecocks need to score more runs if they are to make a school-record fourth consecutive trip to the College World Series.

USC will enter the tournament having lost four of five games, though it also closed 1-4 in 2010 and 2-5 last year. In this year’s four recent losses, USC scored two, three, three and four runs and hit .229. In its other 27 games against conference opponents this year, USC hit .258.

But unlike 2010 and 2012, when the Gamecocks followed sluggish finishes with a home regional, they might have to travel this year — or, at the very least, sweat things out until Sunday night’s announcement.