Santon was not considered for their victory over Palermo last night, despite the youngster being involved in the Italy squad.
Mourinho explained: "When I read that Mourinho does not want to play him, I do not understand. I am the first who wants to play a young man who started out with me. But, as he himself admits, this is not an easy moment for him, on and off the pitch.
"But right now, when he is struggling, this is the time when I take his hand and I stand beside him."