Per Mertesacker feels Arsenal must get their season back on track quickly after back-to-back defeats on the domestic and European stages.
Arsenal slumped to a 2-0 home Champions League defeat against Schalke on Wednesday night, their first European loss at the Emirates Stadium since losing a semi-final second leg to Manchester United in 2009.
Gunners manager Arsene Wenger, who was serving out his three-match European touchline ban, had called for a response to Saturday's lacklustre 1-0 reverse at Norwich, which left them 10 points behind leaders Chelsea.
However, his men failed to deliver with only one shot on target, and that in stoppage time, as second-half goals from Klaas Jan Huntelaar and Ibrahim Afellay dented Arsenal's hopes of early qualification for the knockout stages as the German side took over at the top of Group B.
Arsenal, so impressive before the international break, have a chance for some swift redemption when Barclays Premier League bottom club QPR visit on Saturday.
German defender Mertesacker accepts things have to change again for the better - and without delay.
He said: "We have had a difficult week, our results were kind of an accident, now we have to find our game again.
"The international break was kind of a killer for us. We have to find our strength back again quickly.
"We have the potential in us, but first we have to fight."
Despite QPR's predicament at the foot of the table and with an appalling long-term Premier League away record, Mertesacker says there can be no complacency.
He said: "It is the same as against Norwich, they were bottom as well and we did not find solutions against a defensive side.
"We have to learn quickly from what happened there and against Schalke.
"If we do not find these solutions, it is going to be difficult both in the Premier League and the Champions League as well.
"We have the chance to come back in both, but we have to find ourselves quickly.
"It is our task now to find our self-confidence, we have great players with great potential, but at the moment you cannot feel we are a strong squad.
"So it will be good to have a game in three days so we can show our potential again."
Despite the disappointment of successive defeats, Mertesacker maintains the mood within the group can soon be upbeat again.
The German centre-back said: "We try to be positive in front of the next game.
"In the next training sessions we will look to get our confidence back.
"Sometimes you need one game to find your strength and qualities back, so let's do it on Saturday."
Captain Thomas Vermaelen has backed the Gunners to turn their fortunes around again just as fast as they have faltered.
He said: "It was only two or three weeks ago before the international break (that we won), so it does not mean you lose all of your quality.
"It is a bit negative at the moment because you have two disappointing results, but in football it can turn really quickly and on Saturday it can be different again.
"In these times, you have to stick together as a group, and a club. I am really positive this group has the quality to win games again.
"Every time you have an opportunity to get it straight and that is what we have to do against QPR."
Arsenal could have England duo Theo Walcott (chest) and Kieran Gibbs (thigh) available again this weekend.
However, midfielder Jack Wilshere is unlikely to feature, with his return to first-team action following 14 months out pencilled in for next week's Capital One Cup tie at Reading.