Arsenal manager Arsene Wenger did a post-mortem after Sunday’s 2-1 defeat to Bournemouth and spoke about want-away forward Alexis Sanchez.
Hector Bellerin put the Gunners ahead early in the second half in Dorset, but Calum Wilson and Jordon Ibe struck in quick succession to win it for the Cherries.
"I'm not concerned about the spirit," Wenger said. "I'm concerned when it matters we are not dangerous enough. We looked a bit lacklustre in the final third. Not sharp enough to create chances.
"Overall it was a tough game for us. We were 1-0 up and then we made two very surprising mistakes. They weren't forced errors, just lack of decision making.
"Overall we have to look at it in a very objective and harsh way, we made mistakes we should not have made. The team that fights against relegation will fight and you cannot afford any concentration mistake.
"We had to win the game. I think if you look again at the second goal we made many mistakes and that is what we paid for."
The Gunners travelled to the Vitality Stadium without star forward Alexis Sanchez, who seems on the verge of an exit amid interest from Manchester City and Manchester United.
"Half in, half out, you never know this kind of situation during the transfer period," Wenger said on whether the Chilean would stay or go. "That is why I decided to focus on the game.
"When you look today we missed many players. If he goes, we have to respond. At the moment we try to use players who are completely focused on the club.
"It could happen today, tomorrow or not at all. I didn’t want to travel with him and then he goes somewhere. It will be decided in the next 48 hours. It was difficult for him because he was on standby a little bit."