Francis Coquelin believes it is crucial to Arsenal's Premier League title hopes that they beat Manchester United on Sunday.
Arsene Wenger's men lost 2-0 to Barcelona in the Champions League last-16 first leg on Tuesday, but while their European hopes are on the brink, Arsenal are involved in a thrilling race to be crowned league champions.
Danny Welbeck's last-gasp header secured a dramatic 2-1 win over leaders Leicester City last time out in the league to cut the gap to two points and next up is a trip to Old Trafford.
United have endured a disappointing campaign by their lofty standards and have struggled for goals at home, but Coquelin warned that Louis van Gaal's men will have a point to prove.
"I think it's been a difficult [season] for Man United, but in big games like this, we know that they're going to turn up, because everyone loves these kind of matches," the Frenchman told Arsenal's official website.
"It would be a massive win for them to beat us, but we're going to be ready.
"We beat Leicester and I think the whole team is conscious that, if we want to win the title, we have to win against these kind of teams. Man United are always going to be a great team. Even if they had a bad spell, they still have a strong squad.
"Last year we didn't lose to them away from home [in two matches]. We showed that we can do something against them away.
"We won there in the FA Cup and drew there in the league. We're going to go there full of confidence after what we did last year.
"We've just beaten the team at the top of the league and shown that we have the desire to do well and grab silverware at the end of the season."