Arsenal manager Arsene Wenger says lack of physicality and a number of incorrect referee decisions were the main reasons why his side lost 4-0 away at Southampton.
The Gunners had a golden opportunity to leapfrog Leicester City at the top of the table but were thrashed by a determined Southampton side on Saturday.
They will host Bournemouth next, at the Emirates, on Monday.
"We lost too many challenges and that explains why we lost the game," Wenger said.
"But that's one aspect, so well done to them.
"The second aspect is that on the first three goals we were really unlucky with the decision of the referee.
"The first goal was offside, the second goal was a foul and the third goal was a goal kick, so if you're a bit below par and on top of that you have the first three goals against you in the decision-making then it's even more difficult."