The Serbia international has been linked with Inter and AC Milan this season and faces Mourinho's team tonight in the Champions League.
Krasic said: "He is one of the best in the world. At least 60 per cent of his team's results are down to him. Sure, he has very good players, but he is really special.
"You see that the players listen to him and are ready to do everything for him. I like how he has changed the team: now Inter fight for every ball and play in a more collective way."