Jose Mourinho says Manchester United have some scheduling issues to deal with in the next month or so.
United are through to the Europa League Round of 16 after beating St Etienne tonight with the two legs of the next phase to be played on March 9 and 16.
Between those two dates, the Red Devils must face Chelsea in the FA Cup quarter-final at Stamford Bridge on Monday March 13 which provides Mourinho with a few problems.
"I feel really surprised that the decision is made before our draw in Europe because, in this moment, nobody knows who we play against, nor where the first and second matches are being played," he told BT Sport.
"We play Chelsea on Monday [13 March] then we've got a second match in Europe, Russia or Turkey. This is what we have.
"I cannot play against Chelsea with the second team. I cannot play against Chelsea with the Under-21s, like Manchester City did – was it last year?
"We're Manchester United. I cannot do that. I don't do that.
"As United manager, I don't do that to the FA Cup because the FA Cup is not guilty of these decisions.
"The cup is beautiful, the competition is historical and I have to treat United supporters and the FA Cup in the right way. What is going to happen is an accumulation of matches, people playing lots of matches.
"I will have to make some rotation but some of the boys will have to play all consecutive matches."