Roy Keane claims that Ireland lack the pedigree to be able to dismiss opponents like Gibraltar.
The Corkman sounded the warning ahead of the team's flight to Faro later today for a Euro 2016 qualifier that is expected to end with a comfortable victory.
Keane accepts that Ireland are resounding favourites to collect the three points against a team that has conceded 34 goals in their six qualifiers to date. However, he feels Ireland have not earned the right to be complacent about any team.
"I wouldn't be one for saying these teams don't deserve to be in a group with ourselves, Germany and Poland," he said.
"You could say that about ourselves and give us a few easier groups. The challenge is there for them to improve. We've found it hard to win international matches so I'm not one for saying they shouldn't be allowed in."
Keane anticipates that the senior pros in the Irish camp will deliver the right mentality.
"It can happen," mused Keane, when asked if a low-key atmosphere can lull players into a false sense of security, "But I look at the lads who might be starting and we've a lot of experience.
"The Robbie Keanes, the Shay Givens, the John O'Sheas, these boys. They are real good pros.
"Whether you're playing in front of 80,000 or 90,000 or one man and his dog, you have to do things properly, you have to be professional and in my career I always tried to treat each team with the same respect."