Staffordshire Police have warned football supporters not to head to Stoke-on-Trent on Sunday unless they have a ticket for the FA Cup game. The fifth-round match between Stoke City and Birmingham City could see 20,000 supporters at the Britannia Stadium in north Staffordshire.
Police and the clubs are warning fans that if they arrive without a ticket they will not get in.
Roadworks and the size of the crowd are expected to cause road delays.
Supt Andy Franks said: "This is a vital match for both clubs and we expect a large home and away following at the stadium.
"However, it is vital that anyone intending to watch the match gets a ticket."