Chelsea line up bid to sign Everton midfielder Marouane Fellaini in January

Chelsea are lining up a move to sign Everton midfielder Marouane Fellaini in January.

The Champions League holders are keen to beef up their central midfield as doubts persist over the effectiveness of the partnership between Frank Lampard and John Obi Mikel.

It is understood Chelsea have identified £25 million-rated Fellaini as a battle-hardened Premier League midfielder who can play behind their battery of attacking midfielders which includes Eden Hazard, Oscar, Juan Mata, Ramires, Victor Moses and Marko Marin.

Fellaini revealed during the international break that this could be his final season at Goodison Park, claiming: “in January or at the end of the season I will turn to another club or championship."

Chelsea are ready to test the resolve of cash-strapped Everton, whose manager David Moyes has admitted his club would be vulnerable to a big offer for their prize asset.

The versatile midfielder signed a new five-year contract last November but is concerned about whether his ambitions can be met at Goodison Park.

Fellaini, who became Everton’s record signing when he moved from Standard Liege for an initial €17m (a club-record £15m at the exchange rates of the time) in 2008, is attracted by the possibility of moving to a Champions League calibre club.

Chelsea are in the market for a central midfielder after loaning Michael Essien to Real Madrid and selling Raul Meireles to Fenerbahce.

The Londoners signed Oscar for £25m in the summer but he is regarded as more of a playmaker, while Roberto Di Matteo has been reluctant to use Ramires in the centre since taking the Stamford Bridge reins.

In Di Matteo’s preferred 4-2-3-1 system, Lampard and Mikel have started together in three of Chelsea’s four Premier League games, as well as in the one-off Community Shield and Super Cup fixtures.

But Lampard turned 34 in June, is in the final year of his contract, and is not regarded as a long-term option in the centre, while Mikel has yet to prove that he can be a consistent performer.

Fellaini has been a virtual ever-present for Everton during his four seasons in English football and delivered one of the outstanding performances of the new campaign when the Toffees defeated Manchester United 1-0 last month.

The Belgian has operated off the main striker this season in an attacking midfield role but has generally been used by David Moyes as a midfield anchorman.

Speaking at the end of last week, Moyes made no attempt to hide the possibility that Fellaini could leave in January.

“I won't say there's no chance in the next window because everybody is available throughout the world if the offer is right,” the Scot said. “But one thing I know is the transfer window is closed so he's not going anywhere right now.”