Mikel Arteta has called on Arsenal to use the shock Champions League defeat to Dinamo Zagreb as a motivation against Chelsea.
The Gunners took the long route home from Croatia via Slovenia overnight to prepare for the Saturday lunchtime kickoff at Stamford Bridge.
Arsene Wenger recorded his first ever win over Jose Mourinho in the Community Shield last month.
But Arsenal enter their Premier League re-match after a shock loss which leaves them with an uphill battle to qualify to the Champions League knockout stages.
“It doesn’t help, before a big game,” said the club captain. “We have to react quickly. We’re quite good at that. We’ve done it in the past. Saturday will be a very different game.
“It’s a big game, we have to react. We’re upset and we have to react. Sometimes when you have disappointment in the body it’s good because you find a good reaction.
“We haven’t managed to win three games in a row which is very important. We had two in the pocket and wanted a good result in Zagreb.
“First we have to recover the best we can and start to prepare for the game because we only have 48 hours. We will get back to the training ground at four or five o’clock in the morning.
“We will try to get a good sleep and tomorrow is a new day, a time to be positive and take good things into the next game because we can beat Chelsea.”
With Bayern Munich also in Group F, Arsenal cannot afford to lose another game to Dinamo or Olympiacos to qualify for the last 16 for a 16th consecutive year.
“We know there is no room for error,” Arteta added. “We experienced that last year when we lost in the first game at Dortmund. We still managed to finish second in the group. But it was not the result we were expecting that’s for sure.”
Arsenal started strongly but Olivier Giroud missed early chances – and then got sent off after 40 minutes.
“We could have been two or three nil up in the first 20 minutes,” Arteta added. “And after we conceded a goal with the first chance they had. We were very unlucky. Obviously with 10 men the game is difficult and different. We tried our best but we couldn’t get back in the game.
“I haven’t asked him (Giroud) about it. It looked harsh on the pitch. I haven’t seen it again to judge it. I don’t know but it was a fact that he was sent off but we had to react to that.