CHELSEA legend Charlie Cooke believes Michael Essien is fast becoming the club's key to success.

Essien, 24, has not missed a single game this season and his versatility is a major bonus for Blues boss Jose Mourinho.

The Special One has deployed him in a number of midfield roles while the Ghana international has also filled in at full-back.

And Cooke, who won the FA Cup and European Cup Winners' Cup with the Blues in the 70s, claims Essien is on the verge of earning a reputation as one of the world's best players.

He said: "Michael has always been a great player but he's had an outstanding season so far.

"I keep saying to people that if he can add another four or five goals to his armoury, he'd be one of the most valuable players in the world.

"Adding that finishing touch to his game would put him right up there with the best midfielders."

Cooke, 64, has also tipped his old club to pip Manchester United to the Premiership title.

The Scot said: "You get the feeling that Chelsea are more solid than United.

"They're certainly more settled defensively and are extremely tough to beat.

"Even if the gap between them and United increases over the Christmas period, Chelsea have the ability to make it up at any point."