The Spanish midfielder thinks that desire and attitude will be crucial factors as Arsenal look to avenge their home defeat to Schalke in the return fixture in Gelsenkirchen this week.
He told the club's official website: "We've got another massive game again. We lost against [Schalke] at home, which was a big disappointment and it's going to be a really tough game in Germany.
"We have to bounce back. I think we have to show how much we want to win it and go there and show big attitude.
"I have no doubt about the attitude that we have in the dressing room, and the desire. I think the attitude was good against Manchester United. We all kept trying, even with 10 men."
Defeat to United leaves Arsenal in sixth place in the Premier League table.