Arsenal manager Arsene Wenger is worried the artificial pitch at Sutton United's home ground could cause problems for his players when they visit the fifth-tier side in the FA Cup on Monday.
Sutton play on a 3G surface at their 5,000-capacity Gander Green Lane in South London, which will be an unfamiliar experience for the Premier League club.
Arsenal enter the fifth-round tie as massive favourites and cannot afford another disappointment after their 5-1 loss to Bayern Munich in the Champions League on Wednesday.
But when asked what could go wrong for the Gunners against a non-league side, Wenger said: "First of all the pitch. Secondly their enthusiasm. Thirdly that we are not ready mentally for a big fight and think subconsciously that it doesn't matter."
Wenger had his team train indoors on their own artificial pitch on Friday at London Colney, and said they cannot use the unusual surface as an excuse.
"Look, ideally we would like to play on a normal pitch. Competition is as well to deal with what you face, and we'll face an unusual pitch and we'll have to deal with it," he said.
"We practice inside [on Friday] because we have an artificial pitch. It's not the same as it's a dry pitch, and at Sutton I've heard that's a wet pitch, they water it before the game. So it will be much quicker than what we have."
Wenger has pledged to field "a normal" team for the game, but has opted against using forward Danny Welbeck, who scored twice in the previous round at Southampton in his first start of the season.
Welbeck has only recently recovered from a serious knee injury and played for Arsenal's under-23s in a 2-1 loss to Leicester on Sunday.
The England international confirmed after the match that he would be skipping Monday's tie as the artificial pitch could increase the risk of him having a setback.
Wenger said the surface will have an effect both on players' bodies and the ball.
"The weight on the joints is stronger, you cannot glide, you have to block every time. So it makes the football a bit different," he said. "Because the ball comes to you and suddenly accelerates and doesn't slow down like in a normal game. So you have to get used to it and deal with the speed."