McClung -- a 20-year-old sophomore who averaged 16 points, 3 boards, and 2 assists on Patrick Ewing's GU squad this season -- recently declared for the NBA Draft.

Mac still has the option to return to school, but that's something his hip-hop star cuz tells TMZ Sports should NOT happen ... if NBA teams have a brain.

We asked the Neon Icon how good McClung could be. His answer?

"All-Star level. All-star, ya know? All-Star. Starting point guard, easily."

Riff says he sees similarities between MM and future 1st-ballot Hall of Famer, D. Wade.

"[Wade] was a pretty good college basketball player at Marquette. Went to the NBA, immediately started," Riff Raff says.

"[Dwyane's] about 6'2", 6'3". Mac is 6'2", 6'3". He's not small. He's not a small player, has long arms. People compare him to Jason Williams. Jason Williams is about 6'2", 6'3"."

Obviously, Wade had a great college career (he was an All-American in 2003), was the 5th pick in the draft, and ended up winning 3 NBA titles and making 13 All-Star teams.

So, yeah ... Wade was a legendary player, and "White Chocolate" wasn't too shabby either.

But, when we asked Riff Raff if he truly saw similarities between the ballers, he did NOT hesitate.

"Yes and yes."