NFL's Le'Veon Bell Says He's THE BEST RAPPING ATHLETE AROUND

Le'Veon Bell is firing lyrical shots at any other athletes daring to pick up a mic ... saying there can be only one king of the rapping athlete scene ... and he wears BLACK & YELLOW.

No, not you Roethlisberger.

Bell joined the guys on the "TMZ Sports" TV show and talked all about his second love of hip-hop ... and when we asked if he was a better spitter than rapping baller Damian Lillard ... he didn't hesitate.

Check out each of their skills below ... and you be the judge ... can you say BATTLE?