MICKEY ROURKEI KNOW HOW JOHNNY DEPP FEELS... Calls Amber Heard A 'Gold Digger'

Mickey Rourke stands in strong defense of Johnny Depp after his legal war ... saying he's

been in the same position as Johnny, and he thinks Amber Heard is nothing but a gold digger.

Mickey joined Piers Morgan for an interview on Britain's Talk TV Tuesday,

claiming he's also been blamed for something he didn't do.

He says he went through a costly battle, giving him a bad reputation, and it wasn't until

he'd lost tons of work that the "truth came out" ... allowing him to land roles once again.

Unclear exactly what Mickey feels he was blamed for

he didn't get specific -- but it is true he seemed to be blacklisted in Hollywood in the '90s.

As for Amber Heard, MR says he sees right through her -- he refers to her as "some gold