Arsenal manager Arsene Wenger took time out after his final home game of the Gunners to wish an old rival in former Manchester United boss Alex Ferguson a quick recovery after the Scot underwent emergency surgery for a brain haemorrhage.
Ferguson, 76, was rushed to hospital on Saturday for surgery, with United saying in a statement the procedure had gone "very well" but that a period of intensive care is required for his recovery.
Wenger and Ferguson battled for supremacy in the Premier League during the Frenchman's first decade of a 22-year stay at Arsenal, which will come to a close at the end of the season.
However, they later became friends and Ferguson presented Wenger with a momento on behalf of United on his last visit to Old Trafford as Arsenal manager just last weekend.
"I was with him on the pitch last week. I went to see him in the box after the game and he looked in a perfect shape," said Wenger, who also started his farewell speech in his final home game at the Emirates on Sunday with well wishes for Ferguson.
"He told me he is doing a lot of exercise, and he looked very happy but that kind of accident can happen. We wish him all well and to recover very quickly. He is a strong man and an optimistic man."
The esteem with which Ferguson is held as one of the greatest managers in football history was reflected in the stature of the well wishers hoping for his quick recovery.
Ferguson won 38 major trophies in just over 26 years in charge of United, including 13 Premier League titles and the Champions League twice.
"All the Manchester City fans in the stadium, you cannot find one person who does not wish the best for an amazing person," said City manager Pep Guardiola on the day City lifted the Premier League trophy.
Guardiola then invited a former assistant of Ferguson's, Brian Kidd, who is now part of City's coaching staff, to lead the tributes from their Manchester rivals.
"He?s such an iconic person as everybody knows. There was a really sombre mood yesterday evening and this morning," said Kidd.
"You think Sir Alex is really indestructible, we?ve all been brought up with him."
Following Chelsea's 1-0 win over Liverpool on Sunday, managers Jurgen Klopp and Antonio Conte also sent their best wishes.
"When I heard the news yesterday I really couldn't believe this could happen. He is absolutely the boss," said Liverpool boss Klopp.
"I wish him the best. He will be 100 percent in good shape I'm absolutely sure. I will see him again."
Conte said his Saturday had been badly affected by the news having had the chance to meet Ferguson personally.
"I have had the chance to know him and his wife," said the Italian.
"I understand that this is a special person. Not a normal person.
"He won many titles in his career, but this is a man, not just a manager.
"I have to be honest, yesterday this news changed my day in a bad way. But we hope to see him quickly. Our best wishes to recover very soon."
Arsene Wenger was greeted by Alex Ferguson on his final visit to Old Trafford as Arsenal manager last week, seen here also with current United boss Jose Mourinho