A.J. McLean -- I Can't Wait to Golf with Caitlyn Jenner!

He's already golfed with Bruce Jenner ... but now, Backstreet Boy A.J. McLean says he wants to get Caitlyn on the links too ... and hopefully emerge victorious this time!

A.J. has been golfing for years -- and actually played a round with Bruce (back when she was Bruce) at Jenner's home course at Sherwood Country Club a while back.

McLean says Bruce kicked his ass back in the day ... and now he's looking for some long-awaited revenge -- which he'll be HAPPY to take out on Caitlyn.