"I think the move was perfect for him at this point of his caree," he said. "He was the star at Middlesbrough and I think he moved up to Villa and proved he could be one of the best players in the league.
"I think at the age he's at it was perfect for him to sign for us. I felt he was a player we needed and that we were a club he needed to be at.
"He now has a platform here to prove over the next five or six years that he's one of the best players in the league. He can really nail down that left-side role and make it his own."