The Gunners suffered a terrible opening to their Champions League Group H campaign when going 2-0 down at Standard Liege inside five minutes.

Although they fought back to record a morale-boosting victory with a late goal from Eduardo, it was a harsh lesson in how costly any lapses in concentration can be.

And Sagna, who started on the bench a fortnight ago, maintains the Gunners will be fully focused right from kick-off against Olympiacos at Emirates Stadium on Tuesday night.

"I hope everyone is ready now to give 100% on the pitch, including the forwards because they are the first to defend," the French full-back said.

"Everyone knows we have to be more powerful in defence to be good in attack.

"We have a good team and everyone is able in this team to play good football and we show it."

Arsenal - who have recorded four straight victories following successive Barclays Premier League defeats away to Manchester United and Manchester City - will be without striker Nicklas Bendtner after he suffered minor bruises when his car went off the road.

The 21-year-old was driving along the A1 on Sunday morning towards South Mimms when his car left the road and collided with the hard shoulder fence and a tree.

It is understood no other vehicle was involved in the incident and the forward is expected to be available for the game with Blackburn at the weekend.

Winger Theo Walcott may also be in line to feature at the weekend, having not played at all this season because of a back problem.

Midfielder Denilson is, however, set for an extended spell on the sidelines because of a fracture to his back.

Manager Arsene Wenger feels his side are improving all the time and head into Tuesday's match on the back of a hard-fought 1-0 win at Fulham.

"I believe we have played well since the start of the season and what is worse, but in a good way, is that in the games we have played the best we have not won," Wenger said.

"But we showed that we can beat anybody since the start of the season and we have that belief in the squad."

Arsenal's parent holding company, meanwhile, revealed an increase in turnover to £313.3million and a record profit after tax of £35.2million from results for the year ending May 31.

Wenger said: "I have always worked in clubs who make money and I would not feel that I do my job well if we lost money at the end of the season, no matter what happens on the sporting side, because you put the club in trouble and, in my opinion, that cannot be accepted from any manager."