Warnock was the manager when Joey Barton played for Queens Park Rangers and he knows the player well.
When he heard of the move to Rangers, his top advice was that Barton keeps his discipline. Barton, 33, is renowned for his fiery temperament. However, the coach backed Barton to be a success for Rangers.
"I don't think even he knows if he will cope with it. But we saw a very mature Joey Barton last season. No-one expected him to go through a whole season without the red mist descending.