Mourinho discussed the Swede at today's media conference.
“He was Zlatan in every club so I don't think it is about managers or clubs, it is about him, he's a phenomenal player," said the United boss.
“He didn't want the Chinese money or the American US Dollars, he wanted the most difficult place to play his football.
“Our contribution to him in motivational terms is zero, that's just his nature."
On the pressure of tomorrow's game, Mourinho added: “I am normal, I don't think the players are thinking of the impressive viewing numbers, for us it's [just] a game.
“We are playing to try and win the title and when you do this especially in the first phase of season no match is more important."