The Gunners missed the opportunity to go top of the table yesterday lunchtime when they let a 2-0 lead slip at home to arch-rivals Tottenham, who recorded a famous first victory at Emirates Stadium.

As it transpired, the defeat, a second in a row in front of Gunners fans, did not prove too costly as Chelsea went down 1-0 at Birmingham.

Arsenal, though, slipped back down to third, two points off Manchester United, now behind Carlo Ancelotti's side only on goal difference.

Wenger, however, fully understands there can be no repeat of his team's capitulation yesterday if they are to land a first championship since 2004.

"We missed an opportunity to make a difference with the teams behind us. It is a big concern, a main concern," the Arsenal boss reflected.

"They have the mentality, they want to win. But we have to analyse everything first before I come out.

"I believe some players could not maintain the pace of the game because they played Sunday, Wednesday, and again Saturday, and it's too much."

Wenger added: "But we were 2-0 up and it was all in our hands.

"It is a strange coincidence of facts that happened which are very difficult to explain, even when you are in the job as long as I am."

Wenger had lambasted his side for being complacent when leading their last Champions League game away to Shakhtar Donetsk as the Ukrainians were allowed to get back on level terms before going on to win through a goal from former Gunner Eduardo.

It was a trait which appeared to have resurfaced against Spurs.

"We wanted to keep the urgency and our defensive tightness alive, but it is not the first time that happens and it is one of our weaknesses - many times we have come out and dropped a little bit the urgency when we are ahead," Wenger said.

Arsenal head to Portugal tomorrow afternoon ahead of their penultimate Champions League Group H clash against Braga.

Midfielder Jack Wilshere should be involved having been left on the bench against Spurs following the back problem which kept him out of England duty.

Denmark striker Nicklas Bendtner was absent from the matchday squad, having publicly questioned Wenger's selection policy, but is likely to be in the group which heads off from Luton tomorrow.

Veteran goalkeeper Manuel Almunia may also be ready for a recall, having been sidelined since the end of September with an elbow injury.

Despite losing in the Ukraine, Arsenal are still top of Group H, ahead of Shakhtar on goal difference and three points clear of Braga as they aim to secure safe passage into the knockout stage with a game to spare.