Mikel Arteta said Arsenal's 2-1 defeat to Bournemouth on Saturday was a "big punch in the face", calling on his players to stand up as the club's Premier League title charge threatens to unravel.
Junior Kroupi gave the visitors a well-earned lead after 17 minutes before Viktor Gyokeres clawed a laboured Arsenal back into the game from the penalty spot.
But Alex Scott restored Bournemouth's advantage in the 74th minute and Arteta's team failed to find a response, slumping to their second home defeat in the league this season.
The Gunners remain nine points clear of second-placed Manchester City with six matches to go but Pep Guardiola's men, with two games in hand, are right back in the title race.
The two teams meet next Sunday at the Etihad in a game that could be a potential title decider.
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"It's a big punch in the face, that's what I said to the boys, and now it's about how we react to that," said a disappointed Arteta.
"We were very far from the level that we're shown," he added. "That's for certain, especially in certain areas that are critical and when you play against a team like Bournemouth, they were very clear.
"But again, I don't want to criticise any player, especially here, publicly."
Arsenal, on course for an unprecedented quadruple just weeks ago, have now suffered three straight defeats in domestic competitions.
They remain favourites for their first Premier League title since 2004 following three consecutive second-placed finishes.
MENTAL CHALLENGE
But Arteta admitted he faced a big challenge to lift his players mentally.
"We know what is at stake and the fact that as a club we haven't done it for so long is a reason for that," said the Spaniard.
"It talks about the difficulty but I just want to focus on the things that we can control, dominate and we have done.
"It's not that we have to do a lot of new things that we haven't done, no, let's keep doing a lot of it, or almost all the things that we've done for nine months because that's what has taken us all the way there."
The Arsenal boss said he desperately needed all his first-choice players back.
Absentees on Saturday included Bukayo Saka, Martin Odegaard, Jurrien Timber and Riccardo Calafiori.
"We need everything, first of all we need everybody fit and available," he said.
"So the ones that are not involved, the ones that are not with us, that are really big, important players, we need them immediately with us because then we're going to be much stronger.
"And then the other ones, they need to stand up, me the first one, and embrace this challenge and go for it.
"So today we have to suffer. It's painful, it's a terrible feeling but tomorrow is a different day and if somebody would have said to me in August, we are in this position right now in April, I'm sure we would all take it."
Arsenal face Sporting Lisbon in the second leg of their Champions League quarterfinal on Wednesday after a 1-0 win in the first leg.
Then four days later comes the summit meeting at City that could make or break their season.