Leeds and Chelsea players will be under instruction from police to be on their best behaviour tonight.
The Capital One Cup quarter-final at Elland Road is expected to be played in a heated atmosphere thanks to a long-standing rivalry between the two teams and bad blood between their respective managers, Neil Warnock and Rafael Benitez.
"I'll ask the managers of both teams to speak to the players and ask them to avoid doing anything which may antagonise supporters from the opposition team, Chief Supt Paul Money, of West Yorkshire Police.
"We want the focus to be action on the pitch - and for it not to be overshadowed by violence or disorder. We want to see both sets of fans enjoy what will be an exciting match and I'd ask responsible fans, who make up the vast majority, to not allow the minority of unruly fans to spoil the game."