Jose Mourinho says Arsene Wenger pushed Manchester United, and him, to the limit.
Wenger will face Mourinho for the last time as Arsenal manager when his side play Manchester United at Old Trafford on Sunday, live on Sky Sports Premier League.
Mourinho admitted he has regrets about his own relationship with Wenger, but hopes United fans will give the departing Arsenal boss respect he deserved for pushing Sir Alex Ferguson's title-winning sides further.
"I always feel the biggest rivals are all biggest friends because they're the ones that pushed us to the limits," said Mourinho.
"I think Manchester United fans know that until 2004 for a decade it was between them and Arsenal, Sir Alex and Wenger. They know the great teams Arsenal had made Manchester United better and better.
"I hope they have that feeling, I hope he has a good reaction, or if not good at least not bad at all. He will feel the respect we have."
Mourinho's arrival in the Premier League at Chelsea came at the end of Wenger's most successful period.
His Chelsea side succeeded in displacing Arsenal's Invincbles of 2003-04 to claim back-to-back titles and Mourinho famously labelled the Frenchman a "specialist in failure" in 2014.
"There were little things that would be better without them, some gestures, some little things, it would be better without it," Mourinho added.
"I feel better now without it. No doubt. But when I arrived in 2004, Arsenal was the champion, the Invincibles, and then I arrived.
"They pushed us to the limits. Do I regret negative episodes? Yes I do."