Ten points clear and everything is humming at Real Madrid ... or is it?
The snipers in the boardroom, the clique in the dressing room, those who have consistently let down the club during Pep Guardiola's dominant rein at Barcelona, will have won again if a fed-up Mourinho cannot be convinced to stay by the Real president.
These days, the exasperation felt by Mourinho lines his every media conference. He's managed to drag a young, inexperienced squad in transition, with a senior clique actively working against him, within touching distance of reclaiming the Liga crown from a team many regard as a the greatest the game has seen. Yet, not a week passes without criticism coming from the Madrid media or a disparaging leak from inside the locker or board rooms.
At Inter Milan, Mourinho also had to put up with a hostile local press - but he could count on his players and boardroom being united behind him. And he rewarded that loyalty with a Champions League and Scudetto Double.
The contrast with what he's experiencing at Real is stark - and goes to the heart of the problems that have riddled the club.
The stories of Sergio Ramos answering back during a dressing down and of Iker Casillas going behind his back to make peace with Barca's players after the Super Copa controversy illustrate what is wrong at Real. That this behaviour is condoned by board directors can only add to Mourinho's frustration.
Within a matter of days earlier this year, two quotes laid bare what Mourinho was trying to achieve at Real and the battle he faces.
"You have to remember that the most important person at Manchester United is the manager," Ferguson told the New York Times in January.
"The minute a footballer becomes more important than the manager, your club is dead. The history of the club goes down the drain. I am the most important man at Manchester United. It has to be that way."
Barely days earlier, an unnamed Real director, reacting to Mourinho's arguments with senior players, was quoted in El Confidencial:
"If he demanded the head of (sports director Jorge) Valdano last season, who will he want this time? Iker (Casillas)? (Sergio) Ramos?"
Mourinho recognised how player power has caused disunity in the dressing room and underachievement on the pitch - and has been trying to eliminate it since the end of last season. But while senior players have a sympathetic ear in the board room, Mourinho will continue to be frustrated.
Mourinho needs to be Real's main man. The players must know it is he who is in charge and he who sets the squad rules.
Mourinho managed to bounce out Jorge Valdano from his sports director's job at the end of last season. The decision was reported as a power grab by Mourinho so he could control transfer policy. But the Real coach is happy for Perez and directors Jose Angel Sanchez and Miguel Pardeza to maintain a strong influence in buying and selling. The Valdano push was more about the culture inside the dressing room and not confusing the message he sends to the players.
Which is where Perez must step in. The financial fair play laws, money from the Middle East and Asia, the football landscape in Europe is changing fast. At the moment, in Mourinho Real have one of the few cast iron guarantees of European success available in the game. But he needs to receive the full backing from his board. For as long as senior players feel they can go against instructions without a united reaction from board and management, Mourinho will always feel undermined.
Having (virtually) delivered the title to Perez this season, Mourinho will feel he can leave Real a winner. He will need some persuading to stay. If Perez is serious about Real reclaiming their European crown, then he has to be 'all in' with Mourinho.
No matter if it's a fellow director, or Casillas, himself, if Mourinho takes them on, he'll be doing it for the good of the club and Perez needs to back him to the hilt.