The Italian coach, who was fired at the end of the Blues poor campaign, failed to consider the Nigeria International for big matches.
And the 24-year-old now hopes the next boss at Stamford Bridge will give him more of an opportunity in the first-team, than his predecessor.
Mikel told The Sun: "I had a good start to the season until about January. Then when the club had a bad run, it affected everybody. Everything went downhill.
"I was playing in every game, Champions League and Premier League, but suddenly we had this bad run which went on for about a month or two.
"I had a knee injury in the middle of it as well and was out for four or five weeks.
"When I came back, I wasn't playing regularly - just a few games. It was frustrating for me.
"When I'm not playing, the manager has a reason why he's not picking me.
"Everyone saw how disappointed I was when I was not being picked in the team.
"It's very difficult as a young player but I've learned to deal with it.
"Every season you are going to have a period when things are not going well for you and other times when things are going well. You have to try and manage both.
"I just try to stay professional, train and forget about it. I play when I get the opportunity."
Source: Team Talk
Source: Team Talk