Ole Gunnar Solskjaer admits Liverpool and Everton have an advantage over their Premier League rivals because the two Merseyside clubs are allowed fans at Anfield and Goodison Park.
United were hoping to welcome 2,000 supporters back to Old Trafford for Sunday's clash with Leeds, but the Government's decision to keep Manchester in tier three means that is no longer possible.
Liverpool remains in tier two as Jurgen Klopp's side and Carlo Ancelotti's Everton battle with United for places at the top of the table. Third-placed Southampton and Brighton are the other Premier League clubs able to have fans.
Old Trafford has stood empty since March despite United's insistence that they would be able to safely accommodate up to 23,500 supporters. Solskjaer appreciates it is a difficult situation but believes the club could easily handle the smaller numbers currently allowed in tiers one and two.
Asked if Liverpool and Everton playing at home in front of their own fans has created an imbalance, the United manager said: 'I don't want to say it's not fair that they get the fans in but, of course, it's an advantage for them because everyone loves the support from their own club. So we just wait and hopefully next time we'll be open.
'This is a delicate question to answer because we want fans in the stadiums. I can't see why we should stop the fans coming into the stadium where it's possible. It's such a difficult answer to give.
'I don't think there would be any problem for us at Old Trafford to host 2,000 or 4,000 as well. We can't wait to get the fans in.'
United's home form has been awful this season ahead of Leeds' first league visit to Old Trafford since 2004. They have just one win from six league games, scoring three goals and conceding 10.
It is in marked contrast to their results away from home, with Thursday's win at Sheffield United maintaining a 100 per cent record on the road. United have come from behind to win all six away games, scoring a total of 19 goals.
'I don't think it's a mental issue,' said Solskjaer. 'It can't be because there are no fans here or there. We should be more used to the pitch as well as the surroundings and environment.
'Sometimes it's down to fine margins: who gets the first goal, how the opposition set up.
'Against Sheffield United, you had two teams who want to play on the front foot and press, which creates space for us and them.'