World number 2 Rafael Nadal had only a few seasons where he was ready to compete on a high level after the US Open and 2018 is certainly not among those, struggling with a knee and abdominal injuries and also with a pain in his wrist to miss Beijing, Shanghai and Paris not being able to compete since the US Open semi-final when he was forced to retire against Juan Martin del Potro. Just like in 2012, Nadal will have to miss the entire post-US Open action as he announced the withdrawal from the ATP Finals in London, missing this event for the sixth time in his career due to injuries after 2005, 2008, 2012, 2014 and 2016, competing in just one match in London in the last three seasons! It was a terrible season on hard courts for the 32-year-old Spaniard in general, withdrawing from Brisbane, Acapulco, Indian Wells, Miami, Cincinnati, Beijing, Shanghai, Paris and the ATP Finals, retiring at the Australian Open and the US Open! He won the title in Canada but that is not enough for a player of his caliber, deciding to take some rest and start all over in 2019.
Thus, John Isner will have a chance to make his debut at the ATP Finals at the age of 33, standing as the second alternative player in the draw after Kei Nishikori stepped in instead of an injured Juan Martin del Potro who was forced to miss London as well.
Nadal has won 80 ATP titles but only four of those have come after the US Open, struggling with injuries after a grueling first part of the season and often not being able to compete with his main rivals, especially during an indoor swing where he never had good results.
He will now undergo a small ankle surgery in order to make a fresh start in Brisbane 2019 and play more constant and competitive tennis on hard courts compared to the season behind him. This also means that we don't have the battle for the year-end number 1 spot, with Novak Djokovic securing his place in history after his fifth season at the top of the standings. Rafael Nadal's score after the US Open per season: