Manchester City boss Pep Guardiola admits he could end up in a touchline row with Arsenal manager Mikel Arteta despite the pair's close friendship.
Arteta worked as Guardiola's assistant at City for three years before leaving to take charge of Arsenal in 2019.
The two Spaniards established a strong bond, but Guardiola knows their relationship could be frayed by the growing rivalry between their clubs.
Arsenal are five points clear of City at the top of the Premier League, while the teams meet in the FA Cup fourth round in Manchester on Friday.
Arteta has shown his emotional side with some touchline rants this season, while Guardiola is not immune to letting his temper get the better of him during games.
However, Guardiola insists any row with Arteta would not alter his opinion of his friend.
"Merry Christmas and Happy New Year was the last time we spoke," Guardiola told reporters on Thursday.
"He's a rival, of course he is. He wants to beat me and I want to beat him.
"I know how we both are and in defeat we are not the best friends in the world.
"From my point of view I have a huge respect for him as a person, as a manager. That's not going to change if we're going to fight on the touchline.
"Sooner or later it's going to happen, I guess, but when that is going to happen it's not going to change the respect I have (for him) or anything."
The relationship between the managers adds an intriguing element to what will be the first of three contests between the two sides in the second half of the season.
They still have to meet twice in the Premier League after their FA Cup clash.
Arteta's conduct in the technical area has been the subject of criticism in light of his booking during last week's victory over Manchester United, but Guardiola was happy to defend his friend.
"When you are top of the league they have to undermine you for another reason, and they are doing that right now. I know quite well this situation," he said.
"Anything can happen on the touchline in the moments of the game. I teach him few things but this comes from himself, his mum and dad, his character and that was already there.
"I know him and I had the feeling during the time we worked together that what he is doing is not fake, it is him."