The Rock -- NO-GO FOR WRESTLEMANIA ... Can't Afford to Mess Up This Face!

Sorry wrestling fans, but you ain't gonna smell what The Rock is cookin' at Wrestlemania next year ... 'cause the dude says he can't risk messing up his million dollar face!!

Rock was out in NYC yesterday -- nicest guy ever btw -- when we asked about a possible cameo at Wrestlemania XXXI.

His response -- hilarious ... but it's a little puzzling since he was just on "Monday Night Raw" this week and even got physical with another wrestler.

Worth noting -- the other wrestler never touched The Rock ... it was just The Rock throwing a few punches at the other guy.