Arsene Wenger was able to take the positives from Arsenal's 3-2 Premier League defeat at Manchester United, but bemoaned a lack of concentration in defence.
Teenage sensation Marcus Rashford scored twice as United dealt Arsenal a blow in their title bid, with Danny Welbeck and Mesut Ozil on the scoresheet for the visitors at Old Trafford.
But Wenger sought to remain optimistic as the Gunners face a quick turnaround ahead of Wednesday's clash with Swansea City at Emirates Stadium.
"We played with a lot of intensity, I cannot fault our commitment and spirit and desire but I feel we conceded too easy goals," the Arsenal manager told BBC Sport.
"I think after the game we have to be positive and prepare for the next one. We have another game on Wednesday, they come thick and fast and you want to keep a good mentality.
"We did fight until the end, we had a lot of the ball but I think we could avoid the goals with better concentration.
"I am disappointed because we lost the game but we will focus on the next one.
"This is a fight where you go to the next one and aim to come back even stronger."
Arsenal, third in the table, are now five points adrift of leaders Leicester City and three behind local rivals Tottenham.