Manchester United or Manchester City face the prospect of playing their Europa League fixtures on a Tuesday evening due to a complication with Uefa's rules.
Both City and United crashed out of the Champions League on Wednesday but a third-placed finish in their respective groups have resulted in the two clubs facing the prospect of Europa League action.
United and City have been seeded for next Friday's last-32 draw, however, that has created a potential fixture clash according to Uefa's regulations.
Europa League rules prevent teams within a 31-mile radius of each other competing on the same day, which means one side could be forced to reverse their fixture, therefore forfeiting the bonus of playing their second leg at home, or see their tie moved to a Tuesday evening.
Uefa also look to avoid a Tuesday clash with their Champions League ties, which means that in the event of United or City's fixture being moved, it could see them kick-off early in the evening.
Everton suffered in a similar situation two seasons ago as they clashed with Liverpool and were forced to play Sporting Lisbon at 5.45pm on a Tuesday evening.