The Gunners manager Arsene Wenger says a number of Premier League sides are in race to secure a top-four spot.
Wenger's team secured a 2-0 win over Everton on Sunday and moved into third place.
Ahead of their tie at Loftus Road against QPR, the Arsenal manager expects the race for a Champions League place will go down to the wire.
“The only thing you can say is that it’s very tight,” the Arsenal boss told Arsenal.com. “You look in front and Manchester City are four points ahead of us, and you look behind and there’s plenty of people chasing us.
“If you ask a team who is four points behind us, they will say it’s realistic to try to catch us. Manchester City are four points in front of us, so mathematically of course it is possible.
“United are only one point [behind] and Liverpool three points. There’s a long way to go but once you’re in March the acceleration is there for the final sprint and what you basically have to do is not look too much at other teams, just focus on what you want to do and how you can do it.
“It will be very, very tight and it will be down to consistency in our results and mental strength. That will certainly be needed again on Wednesday night [at QPR].”