Rafael Nadal: Rafa's Major Championship Window Quickly Drawing to a Close

Is this the beginning of the end for Rafael Nadal?

The former No. 1 tennis player in the world has to be pondering that question after Monday’s 6-2, 6-4, 6-7 (3), 6-1 loss to Novak Djokovic at the US Open Finals.

In a great match that took over four hours to complete, Nadal blew a great opportunity to take advantage of a Djokovic injury. After he lost the third set, the Serbian was seen groaning in pain on the sideline as trainers attempted to stretch out his aching back. Through the set he received treatment and used an injury timeout as well.

Yet the 25-year-old Nadal got absolutely torched in the fourth set and lost to Djokovic for the sixth consecutive time.

It ends a disappointing Grand Slam for Nadal, which saw him take home the French Open title and not much else.

His foot injuries were once again a major storyline throughout the season and forced him to retire from multiple tournaments. Watching him on the court, it's obvious he has adjusted his game to try and minimize the pain. This hampers his overall performance when playing the very best players in the world.

He still has the incredible strength and power in his serve, but his return game is really starting to tail off. Djokovic had Nadal running from corner to corner all match and it really started to take its toll on his body.

Sure, Nadal still has plenty of good tennis left in him and he’ll be favored on the clay surface of the French Open. Yet it looks like the hard-court surfaces have become extremely taxing on his body, leading one to wonder if he can win another Grand Slam event at Flushing Meadows.

Maybe I’m overreacting. Maybe Djokovic just had the sort of magical season that comes once every decade.

Or maybe it’s a clear sign that there is a changing of the guard in men’s tennis. Nadal has been the man for the last two years, but now there’s a new sheriff in town.

Nadal will always have the clay-court advantage at the French Open, but other than that—don’t expect any other major championships.