Arsenal lost their hold on first place in the Premier League after their demolition at Anfield on Saturday, but Wenger is confident that they will show their worth against United at the Emirates Stadium.

"It is always a disappointment to lose a game, but I think it was an accident because we have been very stable defensively and we have to treat it like that," the Frenchman told a press conference on Tuesday.

"We have just been on a 10-game unbeaten run. You cannot consider one game as the trend, the pattern of our season.

"It is an accident, not a welcome (one) of course -- a very disappointing one -- but a successful season is decided by how you respond to that."

Wenger spoke out in defence of record signing Mesut Ozil, who produced an anonymous performance at Liverpool that was in keeping with some below-par recent displays.

"He didn't have the best of games on Saturday, but that can happen," Wenger said of the Germany star.

"He works very hard to adapt to the physical level of the Premier League and for me he is an exceptional player. I wouldn't like to put too much pressure on him because he has been a top-class player until now.

"He knows when he is not good enough he will get questioned. That is normal."

Wenger is hoping that France Under-21 forward Yaya Sanogo will be available to feature against United, having spent five months on the sidelines with a back problem.

The Arsenal manager has also given his backing to the Football Association's disciplinary process after Manchester City midfielder Yaya Toure escaped without sanction following an incident at the weekend.

Toure appeared to kick out at Norwich City striker Ricky van Wolfswinkel during City's 0-0 draw at Carrow Road, but after reviewing footage of the incident, a three-man panel of former referees decided not to punish him.

Chelsea manager Jose Mourinho claimed that the decision could set a dangerous precedent, but Wenger believes that it is important to respect the panel's judgement.

"It is a decision we have to accept," said Wenger. "This decision is questioned, and people who make these decisions can answer these questions. I do not know why they made the decision.

"One positive thing is that this committee exists and that the players know that they can be punished even after the game, so that is very positive.

"After that, the decision is made by human beings and then you have to accept we will not always agree on the way the decisions are made."