We don't know what's happening behind closed doors. How popular is Rooney among the other players? How much influence does he have? It's easy for us armchair critics to say that we'd bench Rooney immediately if we were in charge, but a decision like that is not something you pull over-night. A character like Rooney has to be given a chance first, before benching him. And even then hell may break lose in the dressing room. After reading Fergie's biography, I have no doubt in my mind that a player like Rooney could cause a shitstorm for whoever is in charge. Mourinho has just arrived, so he needs to be careful before making big decisions. But if he knows deep inside that Rooney needs to go, then frustration might get the best of him during half-time talks. Who knows how much shit Rooney has gotten in the dressing room?
But unlike Moyes and Van Gaal, Mourinho has a golden opportunity now. With Zlatan, Pogba and Mkhitaryan arriving in the same window and Martial and Rashford stepping up just months prior, there has arguably never been a stronger argument for benching Rooney. All that is left to do now, is to convince the public that Rooney isn't a CM(his final hope). And Mourinho has already done that in an interview! So now that the world can see that it's basically Pogba vs Rooney, the answer is there for everyone with half a brain-cell: Rooney must be benched. Checkmate.
I wouldn't be surprised if Rooney don't start against Leicester. Regardless of the current leak. Hell, Mourinho may already have notified Rooney that he's not gonna start. That could also be what triggered the leak(speculation, obviously).