The ex-NBA star can relate to Ball in the sense that people "sarcastically" poked fun at his unorthodox shooting style back when he was playing in the league.

For the record, Marion says there were a bunch of NBA players who took shots at his form -- "but not during the game cause I be busting their ass."

Now, with LeBron James clowning Ball -- Marion says the future NBA star has to follow suit ... keep hitting shots and everyone else will pipe down.