Wenger admits tactical error

Arsene Wenger admits 'one tactical mistake' cost Arsenal the game against Manchester United after an Andrey Arshavin error led to the visitors' winner.

The home faithful voiced their disapproval when Wenger substituted the impressive Alex Oxlade-Chamberlain for Arshavin in the 74th minute, despite the teenage winger having just set up Arsenal'sequaliser after looking lively throughout.

The Russian then allowed opening goalscorer Antonio Valenciainto the box to set up Danny Welbeck for United's second, sealing a 2-1 win for the visitors.

Manager Wenger refused to dwell on the issue but admits the change was costly.

Costly

"When it was 1-1 it looked like we would win but in the end one tactical mistake lost us the game," he toldSky Sports.

"I do not want to dwell too much on that now but one second of inattention can cost you."

Despite his admission, Wenger went on to defend his decision to bring off Oxlade-Chamberlain in a frosty post-match press conference.

"I can understand that the fans are upset about the substitution, especially when it doesn't work, but he (Oxlade-Chamberlain) had started to fatigue," he said.

"He was sick in the week. Arshavin is captain of the Russia national team.

"You have an 18-year-old kid making his first Premier League start and a player who's captain of his country and they are querying the substitution? Let's be serious.

"I've been a manager for 30 years and have made 50,000 substitutions. I do not have to justify every decision I make to you (the Press). I stand up for it."

The Frenchman concedes the result leaves his team in real danger of not making the top four this season, adding: "It leaves us in a very difficult position. It's a game we couldn't afford to lose."

Wenger thought his players took too long to hit their stride but was pleased with their display in the second half, despite the result.

Nervous

"Overall I would say we had a great second half," he added. "We had a difficult first half where we were a bit nervous.

"In the second half I thought we had chances to win the game. We made a defensive mistake on the second goal but overall we had a great second half. We created chances, we were a bit unlucky.

"You could see we played under pressure today and it took us 45 minutes to get into the game. In the second half when we played with more freedom we were very dangerous."