And the altercation came right at the start of the meeting where the latest act of petulance between the pair is alleged to have taken place.
Before Sir Alex Ferguson’s opening address Mourinho was rushing into the conference room where his other managers had assembled to listen to the legendary Scot.
As the current Manchester United boss looked for a seat he spotted a space near Paris St-Germain boss Unai Emery and Real Madrid coach Zinedine Zidane.
He asked if he could sit there but quick as a flash the response came from Wenger who has sitting nearby:
“It is not possible.”
The incident caused unease at the conference with those nearest pretending they had heard nothing while others are said to have stifled laughter.
It’s just the latest in a long line of bust-ups between the pair which started back in 2004 when Mourinho first came to England.
The Portuguese has accused the Gunners boss of being a voyeur while they duo came to blows at Stamford Bridge back in October 2014.