Arsenal fans are facing a potentially huge headache over their home Europa League game on February 20.
The match has been moved to a 5:00pm kick-off on a Wednesday to avoid a clash with Chelsea's tie.
Both London clubs won their respective groups meaning they will play the second legs at home.
And as all Europa League games are played on a Thursday, Arsenal have been forced to move their fixture to a day earlier by UEFA so that two London clubs don't play on the same night in accordance with official regulations.