Mourinho has been heavily criticised for ignoring Castilla talent this season, but highlighted matchwinner Morata's progress as a counter argument.
"The kid is very strong mentally and hopefully will not become unsettled with all that he is going to read in these days. Who brought him to the first team, gave him three preseasons, and prevented him leaving and gave him a first team contract? It was me," declared Mourinho.
"I was the one who allowed Pedro Leon to leave, yes. But I am not responsible for the departures of Alvaro Negredo and Juan Mata."