Pep Guardiola insists Arsenal would be making a "big mistake" if they decide to sack Mikel Arteta following yet another defeat.
The Gunners were outclassed by Guardiola's Manchester City, who reached the Carabao Cup semi-finals with a comfortable 4-1 win at the Emirates Stadium.
Arteta has not seen his side win a domestic game since 1 November but he opted to make eight changes to the team that lost at Everton on Saturday and, while his former boss Guardiola made seven alterations of his own, the difference in the respective squads was clear for all to see.
Gabriel Jesus, Riyad Mahrez, Phil Foden and Aymeric Laporte all capped recalls with the four City goals, while Alexandre Lacazette had briefly equalised completely against the run of play in the first half.
Back-up goalkeeper Alex Runarsson should have done better with the opener and was at fault for Mahrez's strike as he let a free-kick pass straight through his grasp, while the decision to start Gabriel Martinelli - just back from a nine-month lay-off - also backfired as he limped off injured.
But, with Arteta currently the favourite with most bookmakers to be the next Premier League manager sacked, Guardiola has offered support to his former assistant.
"They will do a huge, big mistake," he told BBC Radio 5 Live when asked about Arteta's future.
"I'm pretty sure they are going to trust him. I understand for the analysts, analyse the results.
"But I was with him many years and I know his incredible quality as a human being and especially as a manager, how he is involved in everything. It's just a question of time and he will do well.
"I'm not on the board. For me they will do a big mistake if they are thinking. They give him the confidence, they won two titles when for a long time ago it didn't happen at this club.
"In this pandemic situation, with injury problems they have and the games they played always they played good.
"But unfortunately these games is our job and it depends on the results. But football changes in one week so quick.
"I can speak about my experience alongside him, one of the most incredible successful teams in English history we had and he was part of this success and it would not be possible without him, and to create something like this you need time like I had in my first season."
Arteta defended his team selection following a tough period of games and a tricky festive fixture list ahead.
"It was a combination of the amount of games that some of them have played, some players could not be involved, and others deserved to play," he said.
"It is a painful moment again, we started the game and conceded a soft goal really early. After that in this moment, to get over that is difficult."
The Spaniard also played down fears of another long-term injury to Martinelli and praised the teenager's impact on his first start since March.
"Gabi has a unique energy and a way to transmit his passion for the game," he added.
"I think he plays the game in a different way to any other player so it is hard to compare him.
"But it is great to have him back, to bring that spirit, that fight and after such a long time to play against this opponent, the way he did it I think in the first half, it is something to be really proud of."