Essien played under Mourinho at both Chelsea and Madrid, and the pair continue to have a good relationship.
The manager travelled to Essien's hometown of Accra a few years ago to see where the midfielder grew up.
The Ghanaian said to 'Sportsmail': "For me, Jose is still the same. He hasn't changed.
"He still has the fighting spirit, he's still going to work hard to change things. For me he is always the same.
"My time at Chelsea under Jose, I mean sometimes he goes hard on us to get the best out of us, we'd go there, go back and change things.
"With me, it worked very well. Everyone is different. Players are very different, every player is very different to every other one. We'll see how things go.
"I've got the talent, I just do what the manager says, that's all I've done my whole career. That's his decision, you have to follow what he says."