Roger Federer is still playing at an elite level at the age of 36 as he attempts to win his seventh ATP title this week in London at the ATP Tours final. Federer is coming off one his best years of his career winning two major grand slams titles at the Australian Open and Wimbledon respectively, winning six titles overall in 2017, and defeating his career rival Rafael Nadal in all four times he’s played him this year. Federer’s winning streak against Nadal now stands at five straight dating back to his 2015 win over him in Basel. Federer’s head to head record with Nadal is tightening at 15-23, in what once was a one-sided rivalry for the past decade in favor of Nadal.

Federer no longer cares about being No.1 player

Federer’s career resurgence at age 36 has been impressive as he looks to close the year out in style with another victory in London this week at the ATP Tours final. Though he will lose out on being crowned as the No. 1 player in the world to Nadal, despite some late tournament victories, the Swiss legend is now at a stage in his career where he no longer cares about the rankings. Now it’s just about just going out there to play and resting his body as he took some time off to recover during the clay court season, deciding to bypass the French Open. He enters this week as the heavy favorite to win the ATP Tours final and the odds have strengthened in Federer’s favor, now that Nadal pulled out of the tournament with a knee injury on Monday night.

A win over Germany’s Alexander Zverev at the O2 Arena tonight gets him into the semifinals.

Federer feared he would never play again after knee surgery

Federer’s level of play in 2017 has been surprising. Just a year ago, the Swiss ended his 2016 campaign under the knife with a torn meniscus in his knee that forced him to pull out of the ATP Finals last season.

Federer strongly considered retirement, fearing he would never play again after undergoing surgery for the first time his career. And though his team had serious doubts he could recover from the Knee Surgery; here he is coming off one his best campaigns of his career and showing no signs that retirement could be in his near future.

The question now is for the 19 time Grand Slam Champion is just how long can he be playing at this level? Only Federer will know when it’s time to call it a career but those closest to him can envision him playing until the year 2020 in which Federer will turn 39. However much the Swiss legend has left in his racket, it’s going to be a thrill to see him attempt to add more accolades in what already has been an incredible tennis career and arguably the greatest of all time.