The treble-chasing Champions League finalists, who have already bagged the Italian Cup, have a two-point lead at the top over AS Roma and are also in great form as they travel to a side long relegated.
Constant media reports about Mourinho possibly leaving for Real Madrid at the end of the season could have knocked a lesser team off their stride but the likes of captain Javier Zanetti can control their match-day emotions like ultra-reliable robots.
"I'm in love with my players and the fans, not Italian football," he told Reuters this week.
Unlike angry Roma, who visit mid-table Chievo Verona on Sunday hoping for a shock scudetto, Siena president Massimo Mezzaroma has laughed off Mourinho's comments.
"It's a way of taking pressure off his own team. He's doing it in a respectable way," he told reporters.
Whether Siena's proud players see it that way remains to be seen and Mourinho runs the risk that they will be extra-motivated for their final Serie A game.
Meanwhile Juve's search for a new coach to replace interim boss Alberto Zaccheroni looks far from over.
Milan and Juve are such a sideshow this term that the game has been moved to the Saturday instead of Sunday so it does not clash with Inter's potential title party in the city.
