Avram Grant insists that Manchester United's stars could wobble under the pressure if Chelsea win their next two games and draw level with them at the top of the Premier League.

United went six points clear at the top of the table after Sunday's 2-1 victory at Old Trafford effectively ended Arsenal's hopes of winning the title.

But a win for Chelsea over Wigan tonight and against Everton on Thursday would put the Blues level on points with Alex Ferguson's side and set up a potential title decider against United at Stamford Bridge on April 26th.

Grant believes that two wins in four days could put United's players under enough pressure for them to start making costly errors.

"I believe that nobody is a computer," said Grant. "Pressure can affect anybody. It can take you forward in a positive way but also you can see that even big players under pressure cannot play like they used to. It can be any team, any player.

"If we win every game I think we will win the title. But it's not easy to win all the games. I said a week ago I didn't believe Man United and Arsenal would do it, it's not easy.

"I can't say we are the best in England but I don't think there is a team stronger than us. I will not say we are the best in the world, even though we want to be, but I can say when we have all our players I don't see a team stronger than us."

Chelsea face Wigan tonight with Grant debating whether to play goalkeeper Petr Cech in a special mask to protect 50 stitches in a facial wound sustained in an accident on the training ground.

Cech has trained with and without the mask but Grant was awaiting a medical decision on whether to risk him tonight.

Cech already has to wear a special helmet to protect the skull he fractured earlier in his Chelsea career and, if he is selected, he could be forced to wear a chin guard until his stitches are removed.

"We are testing a mask," said Grant. "We need to go again with it to see. In one training he wore a mask and in another he was without it. We are checking all the possibilities with him."

Third-choice Hilario will play against Wigan if Grant opts to leave Cech to recover further. Cech's normal understudy Carlo Cudicini has a hamstring injury which could rule him out for the rest of the season.