United and City meet for the first time this season on Sunday at Old Trafford.
Much more than pride is at stake
If Arsenal drop points against Everton and United beat City, they will move back to the top of the Barclays Premier League.
The bad news for Van Gaal is that he has to take his team on an eight-hour round trip to the Russian capital this week to face CSKA Moscow in the Champions League while City take on Sevilla at home.
"Every club at the top of the league has the same problems
But now Manchester City has a benefit because they are playing at home and that is a difference," the United manager said.
"You have the benefit of the recuperation
Manchester City don't have the travel we have so they have more rest.
"There is nothing you can do
They have the benefit.
"We do a lot of things to try and help
We have cold baths, we have warm baths, less training sessions and practice so the freshness is good enough to beat City
But first we have to beat Moscow."
United made the 1,600-mile journey east on Tuesday - the night before they face Group B rivals CSKA.
To help their recovery, the squad will stay in Russia on Wednesday night, rather than travel home straight after the match, as is customary.
At his pre-match press conference, Van Gaal bristled at suggestions Marcos Rojo, who used to play for Spartak Moscow, is not realising his potential at United.
"I didn't know that he played for Spartak but I have seen him in the World Cup in Brazil and he did it very well and he played also for Sporting Lisbon, there I have analysed him," Van Gaal said of the Argentinian, who signed for United from Sporting Lisbon for £16million last summer
"What I like is that he is physically a very strong guy, a good header and his pass is fast
"That we need, always.There is the potential in him to be a very good player for Manchester United."
City boss Manuel Pellegrini did not agree with Van Gaal that United will have a disadvantage on Sunday.
When asked if City held the advantage for their meeting at Old Trafford, he said: "I don't think that will make a difference in the derby
From Wednesday to Sunday you have a lot of days to recover
We are just thinking about Sevilla, not about the travel of Manchester United, and trying to win three important points at home."
Source : PA
Source: PA