New Orleans Saints RB Mark Ingram -- I May Be Short ... BUT I CAN DUNK!!!

New Orleans Saints running back Mark Ingram is 5'10" and 215 pounds ... but dude SWEARS he can dunk a basketball ... and he's willing to prove it.

The former Heisman Trophy winner was hanging out in Indianapolis last night, getting ready to take in the Super Bowl ... when we started talkin' hoops.

Ingram -- who's still nursing a busted foot -- told us, "I CAN dunk ... if you don't believe me ... when my foot gets right, we can go to a court ... and you put your money where your mouth is."