Chelsea defender Khalid Boulahrouz will be out `for some time` after dislocating his shoulder in the 4-0 FA Cup fifth-round victory over Norwich at Stamford Bridge.
Boulahrouz was taken off two minutes before the interval in what was his first start since returning from a knee ligament injury.
But Mourinho refused to let the injury dampen his enthusiasm for the week ahead as Chelsea prepare to face Porto in the Champions League and Arsenal in the final of the Carling Cup next Sunday.
Mourinho said: 'Boulahrouz has a dislocated shoulder so he will be out for some time.
'The only thing not positive was the Boulahrouz injury. If you can forget that, the result was good and we are in the quarter-final.
'The confidence is still there and this week we have two finals. Porto is like a final and Arsenal is really a final.
'The result was a bit heavy for Norwich. They played well and gave us a difficult first half. To be fair I think we were a bit lucky to be winning 1-0 at half-time.
'In the second half, the second goal gave them no chance to react. After that we had a lot of chances and space and I could rest players and start thinking about the game on Wednesday.
'I thought before the game I could give some rest to some players so I left Ricardo Carvalho and Claude Makelele out and put some players on the bench.
'The first moment I thought the game was over, I took off Didier Drogba and Frank Lampard.'
Chelsea owner Roman Abramovich was back at Stamford Bridge for the first time in six games.
He would have been thrilled by a performance that was sparked by a goal from Shaun Wright-Phillips in the 38th minute.
Drogba added the second six minutes after the break with his 26th of the season and two goals in stoppage time from substitutes Michael Essien and Andriy Shevchenko, completed the rout.
But Mourinho was unconcerned whether or not the club's Russian owner was sitting in the stands.
He said: 'I didn't see him, I was watching the game and doing my work. It is his club and he does not have to give explanations when he is not here.
'We work for him and this is his club. So when he is back, he comes back to his house. It is not our house. When he comes back to our dressing room he will be welcome.'
The awful state of the Stamford Bridge pitch also vexed the Portuguese coach, who confirmed it will be torn up in time for the return leg with Porto in the Champions League - even offering to take up a shovel and help out if necessary.
'This was the last game for this pitch,' said Mourinho. 'Tomorrow it is taken up. I hope the next pitch is better for the game against Porto. The competition needs a proper pitch. We want a good pitch from now until the end of the season.
'We are disappointed with the pitch and I told people one or two months ago that the pitch was very bad. I have other things to do but if they need any help I am ready for it because we are desperate to get rid of this pitch.'
Norwich boss Peter Grant was unhappy with a scoreline that hardly reflected the performance of his players.
Norwich lost goalkeeper David Marshall in the 11th minute after he turned his ankle on the controversial surface and they could have taken the lead when a shot from Dickson Etuhu hit the post.
Grant said: 'It was very disappointing but I think the last two goals were down to tired legs.
'We deserved a lot more out of the game. I thought we produced a performance capable of winning the game. I think we had a go at them manfully, especially after losing our goalkeeper, hitting the post and having a shot cleared off the line, you think it is going to be one of those days.
'But the boys kept going and showed great attitude. We have to take this into our league form because we want to be playing at places like this week in, week out and the boys have proved they are capable of doing that.
'There was a lot of sand on the pitch and it is energy sapping. But we never got the just rewards for our efforts and general play. The final thing was missing and that was putting the ball in the back of the net and that was down to good goalkeeping at times and bad misses. '
He added: 'I thought we were always in the game. The lads were brave but we just lacked that quality in front of goal. We are very disappointed with the result but the general play was excellent.'