The Red Devils sealed a deal for Fernandes in January transfer window.
Since then, the midfielder has scored three times for Ole Gunnar Solskjaer’s side and laid on a number of assists.
Mourinho welcomes United in a Premier League clash on Friday night.
Addressing the media today ahead of the game, he said about his compatriot: “He’s a good player, he plays in a good team in a big club. And normally good players, sooner or later, they adapt and they perform.
“In this case he arrived and he found the team also in a good period, a good period of results. I think he’s doing very well.”