UFC face-smasher Dan Henderson had TWO babes on his arm as he left a Hollywood nightclub Monday ... but one of the chicks MAY have been a rebound for one of the best pitchers in baseball.

Henderson -- who recently beat  Shogun Rua in one of the greatest MMA fights ever -- hit Playhouse last night with Detroit Tigers pitcher Brad Penny.

But when they left, Penny went to the car by himself ... and Henderson followed behind with 2 chicks on his arm.