Going deep into the latter stages of the Europa League will only add to Manchester United's concerns about a hectic schedule but manager Jose Mourinho says his side must keep all their options open to get into next season's Champions League.

United have already had one Premier League game, an away trip to Manchester City, postponed after they reached the final of the League Cup and their schedule could see further disruption depending on their FA Cup and Europa League progress.

"The accumulation of FA Cup and League Cup and the match postponement make it really hard for us," Mourinho told British media. "If we progress in the competitions we will be in trouble in May."

Mourinho's side resume their Europa League campaign against St Etienne in the first leg of their round-of-32 clash on Thursday.

"It will be difficult but we don't throw away competitions." he said, adding that the automatic Champions League berth reserved for winners of the Europa League was a huge reason to give the competition their all.

"We prefer difficult and progressing to easy and being out of the competition. The plus is it is another opportunity to qualify for the Champions League. We have two doors still open.

"One is the Europa League but we know we are in the last 32, not even the last eight or four, so there is a long way to go. In the Premier League the door is also open but we still have a long way to go."