Arsenal manager Mikel Arteta apologized for his team's "unacceptable" performance in Monday's 3-0 Premier League defeat at Crystal Palace.
Arsenal's hopes of securing a top-four finish suffered a blow after they slipped to fifth, a spot below Tottenham Hotspur, who have played a game more.
"We weren't at the races today, especially in the first half," Arteta told reporters. "We were late to every ball, soft in the duels and didn't earn the right to play.
"When we did a little bit we were sloppy on the ball and we didn't have any dominance, any sequences of play where we could take some control of the game and we conceded two poor goals.
"Overall it's unacceptable, we put our hands up, apologize, regroup."
Arteta said they had talked about the importance of winning the individual battles.
"We discussed it just before kick-off, the way you win here is when you compete the way you should," he added. "That means you win duels, have a presence and the composure on the pitch to manage certain situations.
"They are a really physical team and the pitch is not the best to do that so you have to find a way to do other things that usually you don't have to do. We didn't manage to do that."
Arteta said defender Kieran Tierney would see a specialist on Tuesday for his knee injury, which kept him out the game.
"The feeling that he had wasn't positive and what the scans showed either. But we have to wait and see what happens," Arteta said.