John Obi Mikel has admitted that the competition for places in midfield at Chelsea does affect him despite the team's recent success.
Three league victories in a row have arrived since David Luiz's move to midfield and Mikel believes that the number of players that can operate in his position creates a psychological battle.
The Nigerian said: "It affects you because I've been here for a long time.
"I've always played with Frank and now I've played with Rami (Ramires) as well - they're all great players. Now I have to play with David Luiz.
"It's just a lot. I think, psychologically as well. You think, 'If I'm playing today, who am I going to play with?' - because they're all great players."
Mikel will be absent from the Chelsea squad while he joins up with the Nigeria squad for the Africa Cup of Nations.
