Mourinho left Chelsea in 2007 and the Blues have had seven managers in the time he has been gone
"The club is crazy, it is. But we have to keep doing our job. We're players,” Mikel told Skysports.
"The board, the owners, make the decision and we have to stick by whoever comes in. I don't know what's happening. It seems another manager is going to come in.
"Mourinho is a fantastic guy. He's a great guy. He's a fantastic human being, on and off the pitch. He knows how to motivate players, how to get the best out of players.
"If you work with him, from the first day he tells you what he wants from you. That's exactly how it's going to be.
"What he wants from you is what you have to give and this is something that he's managed to do well and if he's the one that's coming in it's going to be a massive, massive plus for us.
"Mourinho doesn't let you relax. He doesn't let you sit back and say 'I'm there now'. He wants to push you to your limits.
"That's what he works hard on with the players. But what a fantastic guy he is, outside and inside the football pitch."
Mikel was bought by Mourinho in 2006 and described the young midfielder then as ‘worth his weight in gold’. It remains to be seen whether the Nigerian midfielder will feature prominently in Mourinho’s plans if he returns.