The Rock -- Hey Jimmy ... Look What Happened to My Ring Finger (VIDEO)

3:25 PM PT -- We don't wanna say The Rock isn't all that tough, but -- IT'S FAKE!! A rep for the movie confirms it was a prosthetic hand. Still looks gnarly as hell though.

The Rock just gave Jimmy Fallon a run for his money in the finger department by posting a video of his finger that will make the faint-of-heart pass out.

The Rock's ring finger took a sharp right after ... the result of an accident on the set of "Central Intelligence."

Fallon wins for the gnarliest injury, but Rock wins for sheer determination ... wait till you hear how he resets his finger.