The California college was a top 20-ranked team after a 28 win, five-loss season, but the NCAA selection committee on Sunday did not deem them worthy.

Australia still has strong representation in the tournament, which starts on Tuesday, with Jack White (Duke), Keanu Pinder (Arizona), Dejan Vasiljevic (Miami), Gorjok Gak (Florida), Gabe Hadley (New Mexico State) and Jacob Epperson (Creighton) booking berths in the knockout tournament that dominates sport in the US until the April 2 final.

NCAA selection committee member Bruce Rasmussen said St Mary's were ruled out because of their weak schedule compared to other teams across the US.

He noted 24 of their wins came against poorly-rated opponents.

"We just didn't think there was enough of a resume to put St Mary's in," Rasmussen said in an interview on US TV network TBS.

St Mary's just missed out.

The NCAA selection committee named St Mary's, Baylor, which features Australian centre Jo Lual-Acuil Jr, Notre Dame and USC as the last four teams to be excluded.

The four No.1 seeds are Virginia, Villanova, Kansas and Xavier.

St Mary's, located near San Francisco, has a strong history of recruiting Australians including the NBA's Matthew Dellavedova and Patty Mills.

This year's St Mary's squad has six Aussies and Tasmania's Marty Clarke is the associate head coach.

The team was led by 211cm tall former Geelong Grammar student Landale, ranked the best centre in US college basketball by some US analysts.

Landale was named last week by the Naismith Memorial Basketball Hall of Fame as one of five finalists for the 2018 Kareem Abdul-Jabbar Centre of the Year Award.

Landale averaged 21 points and 10 rebounds.

St Mary's could have guaranteed a place in the NCAA tournament with a win at the West Coast Conference tournament last week but they were knocked out in the semi-finals by Brigham Young University.

Australian Associated Press