While 2017 has been all about Roger Federer and Rafael Nadal, it's been hard not to notice what's missing lately, or particularly, who. Andy Murray, Stan Wawrinka, Milos Raonic, Novak Djokovic and Kei Nishikori have been struggling with injuries, big time. All but Raonic pulled the plug on their seasons early (though he may be next) and all will miss the ATP Finals after being a part of the year-end championships last year.
Nishikori may be missed the most in this section of the season as he is the greatest Japanese men's player in history. The 27-year-old won his second career title in Tokyo in 2012 in front of a home crowd, and pulled off the feat once more in 2014.