The former Real Madrid coach has returned to Stamford Bridge for a second time after a relatively disappointing season at the Bernabeu, but he was welcomed immediately by the adoring arms of Blues fans across the globe.
Mourinho never shied away from a verbal joust during his previous spell in West London, but does it look like some Premier League rivalries are about to be reignited courtesy of the transfer market?
I think he (Wenger) is one of these people who is a voyeur.
He likes to watch other people. There are some guys who, when they are at home, they have a big telescope to see what happens in other families. He speaks and speaks and speaks about Chelsea.
However, that incident was merely the start of a rivalry which continued beyond Mourinho's departure from Chelsea in September 2007, as Bleacher Report featured columnist James McNicholas outlined.
According to newspaper reports, the two managers are now jostling for position in the transfer market.
But was there a coded message to Rooney in Mourinho's comments to the press on Friday, as the Daily Telegraph noted?
Coming just after Wenger had insisted Arsenal could meet Rooney's wage demands, as Mark Irwin of The Sun reported, were Mourinho's comments also a shot across Wenger's bow?
On Friday, David Kent of the Daily Mail reported that the Gunners were monitoring the position of Chelsea midfielder Juan Mata, despite Mourinho's insistence that the Spain international was not leaving the club.
With Sir Alex Ferguson out of the picture following his retirement as Manchester United manager at the end of last season, both Mourinho and Wenger will recognise there is a vacancy for someone to dominate the Premier League.
While the new Old Trafford boss is fast discovering the increased intensity involved at United, most notably during the current uncertainty over Rooney's future, Mourinho appears to have an edge so far.
Moyes brushed off an initial interest from the former Inter Milan coach during an early press conference, but allowed his frustration to show hours after Mourinho took a second nibble at Rooney, as Mark Ogden of the Daily Telegraph reported.
Unless I was speaking double Dutch, I think I've said Wayne Rooney is not for sale.
People are entitled to talk about good players. I’m getting asked plenty of questions about Wayne and I’m sure Jose has been asked about lots of players as well.
But again, I'll keep repeating myself: Wayne is a Manchester United player and he will remain that.
Jose said the same thing: he doesn’t like to talk about players at other clubs. (He did) but it does happen.
Then, on Wednesday, Chelsea issued a statement insisting Mata and David Luiz had not been offered plus cash to United for Rooney "contrary to what is apparently being briefed to press in Sydney" where United are currently on tour, as Sam Wallace and Ian Herbert of The Independent highlighted.
Where the Rooney saga will turn next is anyone's guess, but the twists and turns so far have helped to open up a fiery opening for the new league season.
Which manager is winning the mind games so far? Let us know in the comments below.