Manchester City manager Pep Guardiola believes Premier League leaders Arsenal are benefitting from the patience showed to Mikel Arteta during his time in charge of the Gunners.
Arteta worked as Guardiola's assistant at City for three-and-a-half years before taking his first senior managerial role at the Emirates in 2019.
The Spaniard had immediate success in winning the 2020 FA Cup, but failed to break into the Premier League's top four in any of his first three seasons.
Now Arsenal are well on course to end a 19-year wait to win a league title as they lead City by five points and have a game in hand on Guardiola's men.
The two sides face off for the first of three meetings in the coming months in the FA Cup fourth round on Friday.
"I had the feeling. We knew it when he was here," said Guardiola on Arteta's coaching ability.
"The biggest compliment for Arsenal as well, is for backing him in the bad moments and trusting him, and keeping him and relying on him.
"At the end, you need time, you need investment and the results are there. It is a challenge for us to challenge them."
During Guardiola's reign in Manchester, City have dominated English football, winning four Premier League titles among nine major trophies.
But he has tried to light a fire under his players in recent weeks to revive the hunger that has brought so much success.
Guardiola has even used Arsenal's desire during the first half of the season as the example for his side to match.
"A team with 50 points in one leg (half of the season) is the best. We have to prove how far away or how close we are," added Guardiola on Friday's cup clash.
"I encourage them to look themselves. When they are not happy for many reasons, the only way is to perform better.
"Think in the past is the past. What happened in the past is the past. We get the salary for what we will do in the future. Extend the contract, what we're going to do in the future. The past is done."