If St. John's cuts down the nets in San Antonio next month, call Rick Pitino the GOAT ... 'cause Dan Dakich says a title win for the Red Storm this year would make their head coach the best ever.

Dakich didn't mince words during his sitdown with TMZ Sports this week ... proclaiming if Pitino becomes a three-time champion with three separate programs, he would immediately vault to the top of the all-time greats list.

"Three different schools, three banners?" Dakich said. "Greatest coach in the history of college basketball."

Pitino, of course, won his first natty back in 1996 -- when he led Kentucky to a victory over Syracuse. In 2013, he won his second 'ship, when he helped lift Louisville over Michigan.

He's the only coach to ever win it all at two different schools ... and Dakich made it clear if he adds another ring at St. John's -- Mike Krzyzewski and John Wooden need to clear some room at the top.

Pitino has his work cut out for him to make it happen ... St. John's has a very difficult matchup coming up with John Calipari and Arkansas on Saturday. If it wins that, a potential tilt with No. 1-seeded Florida is on the horizon too.