The Cleveland Browns superstar linked up with Blueface while working out at UCLA on Wednesday ... and the duo decided to see what kinda arm the "Obama" rapper was dealing with.

And sheeeeesh ... the dude has a cannon!!!

OBJ offered to run about a 40-50-yard route downfield ... and Blueface hit him perfectly in stride for the completion. It was beautiful ... and something Browns fans rarely got to see last year.

"Who got the best arm in the rap game?!," Blueface asked OBJ.

"Yeah, you got it!!" Odell responded ... while gifting his new QB his gloves as a souvenir.

TMZ Sports spoke with Blueface himself about his skills ... and he says football was his first dream.

As a matter of fact, he says he could've made it to the NFL if he stuck with it!!

New England Patriots QB Cam Newton was also in on the fun at UCLA ... throwing darts to OBJ and even Blueface ... who creatively edited his one-handed catch to provide ZERO proof he was able to come down with the ball.

Regardless, Blueface is a freak athlete ... maybe the Browns should take a look??