The Football Association accept there are "different circumstances" attached to next month's all-Manchester FA Cup semi-final at Wembley, but are confident it will not cause difficulties.
United take on City in their last four clash over the weekend of April 16 and 17, with Stoke and Bolton contesting the other tie.
Aside from the logistics of getting two sets of rival fans from the same city down to the capital by the same routes, there are other considerations for that weekend.
The London Marathon is being held on Sunday April 17 while Arsenal host Liverpool in the Barclays Premier League the same day.
All relevant matters will be taken into consideration in discussions between the authorities in planning for the semi-finals, but both the FA and the Metropolitan Police are confident they will not throw up too many issues.
"For any Wembley event we would speak to the Metropolitan Police, Transport for London, Brent Council so this would just be an extension of that," said a spokesman for the FA.
"The fact two teams are coming down from Manchester does pose different circumstances as opposed to one from Newcastle and one from London, for example, but we deal with different issues like this on a regular basis.
"There is a lot of sport going on in London that weekend and we will be having conversations with the relevant authorities before we make a decision as to which game gets played when.
"It is not extraordinary in that sense and we are not expecting huge problems or issues over this.
"We will deal with this event the same way we will deal with other events.
"But we will also be talking to rail transport providers who will be bringing fans from Manchester."
The spokesman pointed out the fixture calendar put some restrictions on planning the semi-finals, but said everyone would have been fully aware when the decision was made months ago that they would coincide with the marathon.
"All our scheduling takes place after consultation with the Metropolitan Police," he added.
"It (the marathon) is a major event going on in London so we have to consider that in our discussions but it would be the same if there was a big parade or similar taking place.
"We would have been aware that the London Marathon would be taking place on that day when we consulted all the people involved.
"The schedule at this time of year can be quite difficult and things have been compounded by the fact the Champions League final is at Wembley so the FA Cup final is earlier than usual."
The Metropolitan Police will have a major say on what day the all-Manchester FA Cup semi-final, the first since 1926, will be held but they are fully prepared for the influx of thousands of fans.
"We deal with football matches - FA Cup semi-finals and final, internationals - all the time," said a spokesman.
"We obviously have a lot of experience of dealing with these things and an appropriate and flexible policing policy will be in place."