Chelsea face off in the Europa League against PAOK tonight at home.

And the club have warned the traveling Greek fans they will not tolerate any trouble.

Chelsea want to avoid the issue of traveling fans arriving at the stadium even if they do not have tickets.

In a statement on their official website, Chelsea said: "If you don't have a ticket, don't attend the ground – you won't get in!

- There are no tickets on sale or available.

- Do not buy tickets from unofficial sources as entry with these tickets will be refused.

- There will be extra security checks in operation, including searching and rigorous ticket screening before being permitted access to the stadium site.

- If you do have a ticket, please arrive in good time.

- To ensure safety and security, strict segregation between home and visiting supporters will be maintained."