Arsenal manager Arsene Wenger says the Gunners have to be consistent if they are to qualify for next season's Champions League.
Third placed Arsenal are four points from Manchester City but with only a five-point advantage from sixth placed Southampton.
And the Frenchman admits anything can happen in the top part of the table.
"The only thing you can say is that it's very tight," Wenger told reporters on Tuesday.
"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]."
Meanwhile, the Frenchman says he is very happy with the progress made by 17-year-old Krystian Bielik.
"Very happy, but let's not forget that the boy is 17-year-old," Wenger said.
"[He] comes from Poland and I have taken him in January more for next season because to give a boy of 17 years old six months to adapt to competitive environment like we have here is needed."
