United report Blues to the League

Manchester United today lodged an official complaint with the Premier League over Chelsea's conduct in the increasingly bitter battle to sign John Obi Mikel.

But Chelsea remain confident of signing the Nigerian teenager because of an outline agreement with his club, Lyn Oslo, and doubts over the legitimacy of his contract at Old Trafford.

United are furious over what they perceive as Chelsea's attempt to hijack the deal and have become the second club to report the Londoners to the Premier League this season.

Chelsea face a Premier League inquiry next week into an alleged illegal approach for Ashley Cole after being reported by Arsenal.

In a statement United chief executive David Gill said: "Manchester United has written to the FA Premier League to register the concerns it has over this matter. We have asked the Premier League to investigate formally as soon as possible."

Chelsea have yet to enter into formal negotiations with Mikel but will be heartened by his repeated protestations that he doesn't want to move to Old Trafford. In an interview with Norwegian station TV2 Mikel today claimed that he had been pressured into signing for United by Lyn's director of football, Morgan Andersen, and United's youth director, Jim Ryan.

Mikel said: "I signed a contract with United but didn't do it of my own free will. I was put under a lot of pressure to do that and denied advice from my agent and people I trust."

Chelsea are believed to be extremely confident of their position and are prepared to go to FIFA to prove their case.

Meanwhile, Didier Drogba (leg), Arjen Robben (ankle) and Damien Duff (hamstring) are all doubts for Chelsea's final Premiership match of the season at Newcastle on Sunday.

Frank Lampard will play, despite needing an operation on his toe, with Glen Johnson and Robert Huth set to continue in defence.