Liverpool fans without tickets for the Champions League final are being urged to stay way from the Olympic Stadium in Athens.
Fans are hoping for a repeat of their teams 2005 success
Ch Supt Dave Lewis, of Merseyside Police, expects up to 25,000 Reds fans to pack the ground, despite an allocation of just 17,000 tickets.
Mr Lewis, who is in Athens, said fans without tickets could create problems for those who have them.
About 8,500 officers will be on duty for the final on Wednesday evening.
Mr Lewis, who assisting his Greek couterparts, said the force would be well-equipped to handle any issues surrounding the final.
"If I had over 8,000 officers, I would be confident of handling just about anything," he said.
Thousands of fans are hunting for tickets in the city
On Tuesday, Reds fans continued to arrive in their thousands, some of them hunting for match tickets.
Mr Lewis accepted that many fans had ignored his requests not to travel to Greece without tickets.
He said: "If I'm a realist, I expect the neutral East Stand to be predominantly full of Liverpool supporters. I can ask for tickets myself as I walk around.
"But I would urge fans who have not managed to find any not to go to the ground. It makes it worse for people who have legitimate tickets - they will create problems for their own kith and kin."
Mr Lewis said he thought there might be up to 25,000 Liverpool fans in the ground, which has a 63,000 capacity.
Liverpool and Milan had allocations from Uefa of 17,000 each, provoking resentment from both sets of supporters.
Mr Lewis said six people had been stopped from leaving the UK in the ports and airports operation designed to stop troublemakers heading for Athens.
Four people were also stopped at Dover for alleged possession of forged tickets, though Mr Lewis had no further details.
Liverpool take on AC Milan in the Champions League final on Wednesday evening.