“I think Ryan is absolutely fantastic, I have known him since a kid in Fulham," Mourinho said. "When he comes to the first team in the Premier League it is different to the Championship.
“I think in this moment he is a winger on the left, can also play on the right, can learn progressively and even develop physically, which he is doing.
"Even from the last time I saw him and the first time I met him when I came here he is already different physically.
“I think Ryan can play as a left-back. Probably the left-back in the last decade was Ashley Cole, in spite of him being from two enemy clubs, but he was fantastic.
“But Ryan has lots of similarities with Ashley, and he can learn how to defend."