Mourinho believe they still have a great chance of winning the Premiership title this season.
He said: “We believe, we have to believe. Anything is possible in football. If we have the best players to play every game there is no doubt about it.
“United deserve respect, They won and in the best way. They have no injuries to their best players and they are fighting. The manager, the players, the club, deserve respect.
“Our job is to fight them, go back to six points behind them and keep the pressure on them.
“We started the day 12 points behind them and now we are nine. If we win our game in hand it will be back to six and they still have to come to Stamford Bridge.
“We have to wait for them to drop some points but I said last season when we were top that the pressure is always on the second team. That is still the case.
“They have to drop four points and that is out of our hands. But 10 games is enough.”