Pep Guardiola says he is wary of the damage Zlatan Ibrahimovic can cause Manchester City in Saturday's derby.
City's manager famously had a difficult relationship with Ibrahimovic at Barcelona, where the Swede played just one season before he was sent on loan to Milan.
Ibrahimovic made his feelings plain in his autobiography, calling Guardoila "a spineless coward", but ahead of the season's first derby at Old Trafford the Catalan spoke in glowing terms both of his former striker and his old Real Madrid rival Jose Mourinho.
"There's no doubt about Ibrahimovic's quality," Guardiola said at his pre-match press conference. "I have a lot of respect for what Zlatan has done for football.
"He's one of the best players and of course the best players impact the way they arrive in the clubs with the talent immediately. Some players have to understand the league - the best players do it quickly and he's one of the best ones."
Guardiola has repeatedly sought to play down a rivalry with Mourinho which descended into bitterness when the pair were in Spain.
According to City's manager, a recent meeting has helped their relationship thaw to such an extent that he is prepared to share a post-match drink with his United counterpart on Saturday.
"I said it many times - I have a lot of respect for Mourinho," he said. "I always try to learn from all of my colleagues - it's the same with him. The rivalry is more from the media and we can't control that.
"He was my coach, my assistant coach with Sir Bobby Robson [when Guardiola was a player at Barcelona]. Okay, the last period at Barcelona and Real Madrid was not easy for both of us but we met each other two, three weeks ago at the manager's Premier League meeting.
"We spoke fluently with Ronald Koeman and Tony Pulis. It was correct, so that's all. Of course I'll accept a glass of wine after the game if he invites me."
Guardiola's approach this weekend will be the same as ever - "I want to control the game" - but he has been impressed by United's improving performances this season and admits set-pieces could prove a problem.
He said: "I saw the official games United have played and in every game they've played better than in the one before. Like us.
"That is normal and of course they have a lot of talent in front - Martial is so fast, Mata between the lines is so dangerous. The quality of Rooney, there's no doubt about Ibrahimovic's quality.
"Set pieces with tall guys it's impossible to control that, they're taller than us. They're a top team, like Manchester United always is."
City captain Vincent Kompany is still not ready to play, but new signings Claudio Bravo, Leroy Sane and Ilkay Gundogan are available.