Mikel has become a first-team regular again following Guus Hiddink arrival as manager.
The 29-year-old was behind Cesc Fabregas and Nemanja Matic in the pecking order while Jose Mourinho was in charge at Stamford Bridge.
Mikel scored in the 2-1 away defeat by Paris Saint-Germain on Tuesday in the first leg of the two sides’ Champions League last-16 clash.
The Nigerian midfielder’s current contract expires next season.
