“I think he's developed incredibly well at every level,”said Mourinho (via Manchester United officical website).
“Physically, amazing development. He was a fast, fragile boy and now he's a fast, strong man. He hadn't psychologically adapted, coming direct from a small club in Switzerland [FC Basel] to a big club in England and the Premier League [Chelsea]. It was too much.
”Now he plays everywhere against any team - completely different than the potential player we bought from Basel to Chelsea. He was a project player then and now he's one of the best players in the world. So I don't think the fact that I know him helps me, because I knew the project player and now he's a top player.
“ he added.