Both were team-mates at Barnsley in the late 1970s, when McCarthy used to clean Warnock's boots, and have remained friends ever since.
McCarthy told the club's website: "He (Warnock) is somebody who gets the best out of his team whenever you play against him.
"I respect what Warny has done in the game with his teams. You go through what he has done through the leagues with Notts County, he has got promoted with Sheffield United, promoted with QPR - there's not (any managers) done it with two different teams from the Championship to the Premier League.
"His record is terrific. He has that way and players stick with him, he gets the best out of them. Wherever he has been his teams are always competitive, and they will be here."
Warnock has made plenty of enemies along the way but McCarthy has always got on well with him.
He added of their Barnsley days: "I got in the reserve team with him and I thought he was great. He was good fun.
"He'd have been like everybody else, I would have liked to have kicked the living daylights out of him in training because he was a winger. But he's a Sheffield lad, a Yorkshire lad - I just got on well with him.
"I don't know why he riles other people, if indeed he does rile them - it doesn't bother me that.
"He was one of the first to wish me well when we got up, and at the end of the season. He never rubs me up the wrong way. I just have a lot of time for him."