The Gamecocks (21-9) were co-champions of the Southeastern Conference Eastern Division, yet missed out on the NCAA tournament.
They were picked for the NIT later Sunday night and will open at home Tuesday night against Davidson, regular-season champions of the Southern Conference.
South Carolina players watched the NCAA selection show at the home of first-year coach Darrin Horn. While they were disappointed not to make the field of 65, Horn reminded them they had a strong season and had more basketball left to play.
"We're a 20-win team with postseason coming, that's progress," Horn said.
The Gamecocks won back-to-back NIT titles in 2005 and 2006 under Horn's predecessor, Dave Odom.
South Carolina improved from their 14-18 mark of a year ago, won 10 games in the SEC and had hopes of an NCAA at-large bid. The Gamecocks, though, lost three of their final four games, including a first-round SEC tournament loss to eventual champion Mississippi State.
However, when Horn saw how the tournament selection committee seeded the SEC's three league teams that made it, he said: "I don't know that anything we did in the last 10 days would've mattered short of us winning" the SEC tournament.