Lampard sustained a fractured bone in his wrist while on international duty with England for their Euro 2008 qualifiers against Israel and Andorra.

The injury prevented him from playing in the 3-0 win over Andorra but he has trained for the last two days with the Chelsea squad and assistant manager Steve Clarke confirmed that he would play against rock-bottom Hornets at Vicarage Road.

Clarke said: "Frank is good. He has trained the last couple of days with a cast on and he is much more comfortable with the injury. He will play against Watford."

Clarke also rejected suggestions that Lampard wanted to come home from international duty once he knew the injury would rule him out of the Andorra qualifier.

Clarke added: "The boy was injured and he couldn't play in the match. The decision was taken not to play him, not to risk him against Andorra.

"He was happy with that decision and he is happy to be back here at Chelsea.

"His return was never an issue. We didn't ask for him to come back and he never asked to come back. He stayed with the England squad to support the team and that is the end of the matter."

Lampard's performances for England have come in for heavy criticism together with the rest of Steve McClaren's side.

The midfielder has scored 20 goals so far this season for the champions but has not been able to reproduce the same kind of form at international level.

Lampard had a difficult World Cup campaign in Germany and his performances during England's Euro 2008 qualifiers have shown no significant signs of improvement.

But Clarke was unconcerned when asked why Lampard cannot recreate his club form for England and added that Chelsea always manage to get the best out of him.

Clarke declared: "Whenever I watch England play, Frank always gives 100-per-cent for his country in every game he plays.

"If people want to criticise his performances for England, that is not a concern for me.

"I think when he plays for Chelsea, everyone knows his value to the club.

"We appreciate what he does for us and we are very happy with his performances.

"But we can only get the best out of Frank Lampard when he is with Chelsea and I think we do that."

Clarke's own future at the club has been the subject of intense speculation this season, along with coach Jose Mourinho.

The Portuguese coach insists his backroom staff do not need a contract as they have a job for life with him - wherever he goes.

But Clarke's current deal with the club expires in the summer and there has been speculation that it will not be renewed.

However, Mourinho's number two says he expects to be at the club next term although he revealed there had been no discussions over a new contract as yet.

Clarke added: "I expect to be here next season, yes. I haven't spoken to them yet but I would expect to do so sometime before the end of June because that's when my contract runs out.

"I will wait until the end of the season. I want to concentrate on what we have to do this season and then we will take it from there."

Chelsea could go nine points behind Manchester United at the top of the Premiership by the time they kick-off against Watford.

United face Blackburn at Old Trafford at 3pm while Chelsea get their game underway at 5.15.

But Clarke insists they are not worried by United's opportunity to put more pressure on them.

Clarke said: "Watford are fighting for their lives and they no they need to win the match.

"We are fighting to be champions again and we know we need to win the match.

"We have to win all our games. The mind set we have is to go out tomorrow and win. It does not matter what Manchester United do before us, because we have to win the game."