I do think if Chelsea progress in the CL they might find things tricky. They've often suffered European hangovers this season and if they get to the semi-final then the Anfield game is sandwiched between these. Liverpool do play a very intense and energetic game. On a related note, given that United will have played two extra games in the past week compared to Liverpool (and I hope Olympiakos goes to extra time ) it will be interesting to see the impact that has on Sunday.