Charles Barkley: Ben Simmons Ain't NBA Ready ... Stay In School, Kid

Bottom dwelling NBA teams hoping to land LSU freshman Ben Simmons are WASTING THEIR TIME ... 'cause according to Charles Barkley, Simmons isn't ready for the big time just yet.

We got Barkley out in NYC and asked if he thought Simmons -- the consensus #1 pick in this summer's draft -- was ready for the NBA after just one season down on the bayou.

It's not a crazy question ... LSU has struggled this season and as good as Ben looks, some wonder if the lack of team success means the 6'10" walking double-double has a little more learning to do.

Count Barkley in with that crew ... telling our camera guy that in his opinion NO KID should leave school before two years in ... and Simmons is no different.

Check out the clip.