Soccer:Arsenal manager Arsene Wenger wants his side to make amends for Saturday's defeat to Chelsea when the Gunners take on Olympiakos in the Champions League tomorrow.

The north Londoners saw a successful start to the season abruptly halted at the weekend as they fell to a 2-1 defeat to Chelsea at the Emirates Stadium. Arsenal sit seven points shy of the Barclays Premier League leaders as a result, but attention now turns to their Champions League campaign.

Wenger’s side takes on the Greek champions tomorrow and the Frenchman wants to see an improved performance in the Group B encounter. “The players are focused and disappointed that we lost the game.”

“They are still down of course, but we have a Champions League game in front of us at home and we want to put things right. There were a lot of positives in that game as well, what was not good is easy to correct.

“I believe the championship is long, but we have to make sure the Champions League is long as well. It is about how we respond. I am impressed by the mentality of my team, but the mentality is as well about how you respond to disappointment. I am confident we will, but that is what we want to show tomorrow.”

Arsenal will be hoping to make it two wins from two Group B games tomorrow, having returned from Montpellier with three points on match-day one. Olympiakos, who Arsenal also faced in the group stage last year, are without a point after losing their opener at home to Schalke and Wenger knows tomorrow’s clash at the Emirates provides a chance to take a stranglehold on the group.

“Olympiakos are already in a position where their backs are to the wall because they have lost at home and in this Champions League when you lose at home it is very difficult,” the Frenchman said.

“They are highly motivated to know they have to give everything to make it through. They are experienced and basically it is the same team (as it was) at the back of last season. I think they had a difficult start against Marseille and after became stronger and stronger through the competition last year.

“It looks similar this year; they had a difficult start at home against Schalke and if you analyse their team it is 90 per cent the same as last season.” Wenger, who is still serving a three-game touchline ban, will have to do without several key players tomorrow night.

Goalkeeper Wojciech Szczesny is still three weeks from a return from an ankle injury, while midfielder Tomas Rosicky and right-back Bacary Sagna remain sidelined.

Wenger revealed playmaker Mikel Arteta faces a fitness test on an ankle injury tomorrow morning, while midfielder Abou Diaby faces a three-week lay-off with a thigh strain that forced him off against Chelsea.

“Arteta will have a test tomorrow morning,” Wenger said. “We will make the decision then whether we include him in the squad or not. He has an ankle injury. We lost Diaby, who has a thigh strain. He is definitely out for three weeks as well. Apart from Diaby and Arteta, everyone came through well.”

Wenger was far more guarded when asked about another midfielder, Jack Wilshere, who came through his first match in 14 months yesterday. The 20-year-old has struggled with an ankle injury suffered prior to last season but stepped up his comeback by playing 63 minutes of the Gunners’ under-21 game at West Brom.

“He came through it all right. There was no reaction. We are pleased but it is now down to taking the right time to ease him slowly back. We are all very happy, and he especially must be exceptionally happy, but he has been out for 14 months.”