Honestly, I feel like Nadal's 2015 is just Federer's 2013. They were even roughly the same ages. Nadal will probably go away, redesign his game a bit, and come back as a top player, if not a dominant one, the same way Federer came back in 2014. It's not even like Nadal is physically unwell or has knee problems at the moment, mentally he's just not there. That will come back in a bit, especially when he sinks down the rankings to #10, does what Murray and Federer did when their ranking slipped and play a lot more minor tournaments, and rack up some wins to regain confidence. I think counting Nadal out is premature [from his career, I mean. Not this match].