Chelsea are now just six points behind leaders United but Mourinho is lamenting the prospect that they will not be able to reduce the gap yet further because of their possible involvement in the FA Cup semi-finals.

Chelsea and United are both expected to reach the last four of the competition and that means their Stamford Bridge showdown, currently set for April 15, will have to be rescheduled.

The prospect is an unpalatable one for the Chelsea boss, who knows they cannot afford to drop any more points.

Mourinho, preparing for the visit of Sheffield United tomorrow, declared: "(United) have a few injuries but our situation is not improving. We have lost Wayne Bridge and Michael Essien - Bridge for three weeks or one month and Essien not for so long.

"I still think in relation to the Premiership, their position is better than ours. That is obvious. They have six points more but the good thing is that we are winning matches. I think in the last 27 or 28 matches in every competition, we have lost one. In the Premiership, we keep winning matches and keeping our hopes up in relation to the title.

"It is a pity we don't play Manchester United - it would be much better to play them now and have the chance to reduce the difference from six to three - after that everything would be open.

"They would be feeling the real heat. In this moment, we don't play against them because one of us will be in the FA Cup semi-final, or both or no-one.

"But there is a chance we don't play them. If we don't play them we have to wait for them to have a bad result but I still think they are in a better position than us.

"But at the same time my team is strong, has self-belief and we are ready to go all the way.

"The situation is in their hands. If they win every game, there is nothing we can change - nothing we can do."

But Mourinho bemoaned the fixture congestion his side is facing as they approach the most crucial part of the season - suggesting that the odds are stacked against an English team winning the Champions League as a result.

Mourinho added: "This period of April and May is unbelievable. I don't know how we can get into this situation.

"If you go to every other country involved in European competitions, they have a much better situation to deal with.

"I think it goes against the possibilities the English clubs have to succeed in Europe. We play against Valencia and we have two more matches to play than them in this period, so every team abroad can prepare and concentrate on the job for the Champions League and here it is very, very difficult.

"But if you tell me we play Manchester United in the FA Cup final and the Champions League final, I would be jumping with happiness and maybe Sir Alex would be the same because it means we go to the limits.

"But we have walls in front of us and we have to beat them. We have two big games in the FA Cup against Spurs and Blackburn first.

"I don't change my words - the next team to lose points will be in a difficult position. Six to eight or nine points is comfortable for them. Six to four or three for us is what we need for the extra bit of motivation to have in our pockets."