Sagna picked up an ankle injury during the build-up to Villa's opener in the 2-0 win and could be out for a "few weeks" after being carried off on a stretcher, according to Wenger.

Cesc Fabregas received a yellow card in the move that led to Ashley Young missing a penalty in the first half, with the Arsenal midfielder now facing a suspension for the trip to Manchester City next week.

After defeating Manchester United last week, Wenger feels Arsenal need consistency if they are to mount a title challenge.

"The performance was not good," Wenger said. "Top-level performances are about consistency and at the moment we are not consistent enough."

Young won the 20th-minute penalty but had his spot-kick saved by Manuel Almunia, but he helped set up the opener in the second half.

Gabriel Agbonlahor looked to get on the end of Young's cross but Gael Clichy appeared to get the final touch as is flew past Almunia.

There was no doubt about the second goal, Agbonlahor holding off William Gallas and firing into the near post, although Wenger felt play should have been called back.

"It was a blatant foul on Carlos Vela on the edge of the box," said the Frenchman.

Wenger also bemoaned the fact the international break gives him little chance to lift a demoralised dressing room.

"Everyone is very down, it is a massive disappointment," he said,

"Now I don't see them before Thursday or Friday, so I don't have [chance] to pick them up."

Villa boss Martin O'Neill was impressed by his side's performance and he too is looking for consistency if they are to challenge for a place in the top four.

"I thought we were exhilarating," he said. "We were fearless.

"We have ability in the team, mark my words, it's getting them to believe they can keep going.

"You have to show a bit of character and determination after two defeats and I thought that we showed that in abundance.

"The landmarks are to do with consistently performing. It was a great performance but it's a tough old season."

Villa are unbeaten at the Emirates Stadium in the three visits since it opened, and O'Neill feels the quality of performance shows how they have progressed.

"The first year, we drew here in our opening game but we could have lost 35-1," he said. "Our progress since then has been fantastic.

"We beat and drew with Chelsea last season as well. That doesn't necessarily mean much because winning one-off games can only get you so far and it doesn't mean we can win every week.

"But this will give the players great confidence, particularly in the way we missed the chances but didn't let that affect them."