Arsene Wenger said it "hurt" that his players' attitude was questioned and believes Arsenal passed a "mental test" to beat Everton on Saturday.
The Gunners were knocked out of both the FA Cup and Champions League this week.
"I was pleased with how well they responded today," said Wenger.
"It was a very significant win for us and a mental test.
"I like this group, I like the mental attitude, it has been questioned and that hurts me," he added after Danny Welbeck and Alex Iwobi scored in the win over Everton.
"When you work with them every day, you see how much effort they put in."
Arsenal were top of the Premier League on 4 January and fighting for silverware in two cup competitions.
But their form has collapsed in recent weeks and Saturday's win was their first in four games in the Premier League.
They are now 11 points behind leaders Leicester City and three behind second-placed Tottenham.
But Wenger does not think his side are out of the title race with eight games remaining.
"Why should it be a two-horse race with one team three points in front of us? Let's focus on performances and after that we will see how we finish," he added.