I sense Nadal wont win any masters prior to USO.
People forget easy, but outside of his tournament, RG, Rafa looked beatable in every tournament so far this year.
In the grass season he lost to a top200 in Nick Kyrgios, weeks earlier he lost to ***** Dustin Brown in the first round in straight sets.
During the clay season, he lost to Nole in the finals of Rome but he looked bad the whole tournament. Needing 3sets marathon wins to beat guys he usually destroyed, like Youzny, Simon... Then went 3sets as well against murray, losing the first one 6-1...
He won the Madrid Open but getting outplayed by Nishikori in the first set. Key had a marathon in the semis and played injured that match and had to give up in the 3rd set.
@Barcelona Open he host to another guy he usually destroyed in Almagro in the 3rd round and struggled even against Albert Ramos in the first round...
@MC he was straight setted in the QF by one of his clay pigeons, Ferrer.
@Miami he was utterly dominated by Nole in the Final after struggling to beat Raonic in the QF in 3 hard-fought sets and then had a WO to the FInals.
He did even worse at Indian Wells, losing to Dolgopolov in the 2nd Round... A guy that he had beat few weeks before at Rio's Atp500 but in the semifinals of that tournament he needed to save match points against also one of his pigeons, Pablo Anjudar.
Nadal still a nightmare to be beaten in a BO5 tournament, so I wont rule him out of USO but I don't see him winning any of the masters prior USO.