O'Neill, who has never enjoyed success in this competition as a player or manager, is well aware of the dangers.
O'Neill said: "They are there to see us get beaten. Three years ago, when I was at Villa, we played at Gillingham and they caused us all sorts of problems.
"We had England internationals in the team - James Milner, people like that were playing.
"We were lucky we won eventually, lucky to survive. So I know the feeling.''