Florent Malouda has admitted he could leave Chelsea if he does not get a regular run in the side.
The Frenchman has found first-team opportunities hard to come by because of Carlo Ancelotti's change in formation.
Malouda has been relegated to the bench because of Ancelotti utilising a 4-3-1-2 system this term.
French international Malouda enjoyed arguably his best season at Chelsea in 2008/09 and he is frustrated at not being first-choice in Ancelotti's starting XI.
Malouda has spoken to Ancelotti about his frustration, but he revealed the club will not allow anyone to leave before the end of the season.
Malouda told L'Equipe: "Carlo Ancelotti's tactical system is physically very demanding. Recently we showed less intensity, the game was less fluid. But that system allowed us to be in our current position. All the players support it.
"Before the match against Birmingham, I talked to the coach. I told him about my frustration.
"I believe I have succeeded in my start to the season, but during the key matches against Arsenal or Man Utd, I was on the bench.
"I have ambitions for the World Cup, and considering my status in the French team it is a little annoying (being on the bench).
"Ancelotti is aware of it. But currently I am paying for that system. It is not that easy for him either, he has a big group to manage.
"My competition with Lampard as left midfielder? It is his best position. He played like that in the England team, and we are in a World Cup year.
"But at a certain point, the status has to be in relationship with the performances.
"Anyway, I am fine so far. I could still be outstanding when I play.
"The frustration is big matches. However, if there is no place for me in that system, I could go somewhere else.
"Finding a new club is not a problem. But the club has closed the door to any departure either in January or in June. The coach relies on me.
"I feel fine at Chelsea. But now, things have to change. When I came I was labelled as Mourinho's player. I have known five coaches and each time I have had to start again from scratch.
"Last season I earned a key-player status. Today it has been questioned again."