• Novak Djokovic

Novak Djokovic (Photo : LatinContent/Getty Images)

Novak Djokovic's reign as the dominant force in the ATP World Tour could be nearing its end even with fierce rival Roger Federer out of competition due to injury.

Federer has always been a threat to Djokovic's reign in the past two seasons, having met the world No. 1 in final rounds of tournaments 10 times since 2014. Most of Djokovic's win over the Swiss Maestro were during Grand Slam events, forming one of the greatest rivalries in the Open Era.

Like Us on Facebook

Injuries and setbacks incurred by Federer limited their chances this season of handful of epic matches, but despite all that, Federer is still considered as the few who could challenge and topple Djokovic. But interestingly, even with Federer skipping the remainder of the season after re-injuring his surgically-repaired knee, there are still those who are ready to dethrone Djokovic from his seat.  

The 2016 Rio Olympics brought out plenty of surprises this season, including Federer's leave of absence until next year and the sudden rise of Andy Murray, Rafael Nadal and Juan Martin del Potro as strong contenders to completely derail Djokovic from his winning ways.

Del Potro came as stunning revelation in Rio after kicking off his campaign with a victory over Djokovic. The Argentine also posted notable wins over Stan Wawrinka in the second round of this year's Wimbledon and beat Nadal in the Olympic semifinal.

Del Potro slipped from world No. 4 to rank 141 after undergoing three surgeries in recent years and missing a chunk of competitive matches in the last two seasons. But the 27-year-old Argentine has suddenly turned the tides in Rio, earning him a Silver Medal at the quadrennial event and a wildcard at the US Open, where he has the chance to compete against top players once again.

"You give it to players that are deserving," Murray said of Del Potro. "Juan Martín deserves to be playing in the Slams, because if he hadn't had his injuries, he would be comfortably seeded in all of the Slams. The reason why he's not been there is because he's been injured."

Nadal also came out impressive in his stint at the Olympic Games, winning a Gold Medal for Spain in doubles competition with compatriot Marc Lopez. While the King of Clay fell short in winning a medal in the men's singles category, his remarkable run at the event still gained him the much-needed confidence heading into the next tournaments.

After gaining back some of his mojo during the European clay-court circuit, a left wrist injury halted Nadal's quest in finding his old form. The injury forced him on the sidelines for more than two months, but after participating in Rio, Nadal seems ready to get back in tennis action.

"I know I was ready this year to have strong results in Grand Slams. I get injury. I was unlucky.  But I feel competitive again.  I feel with the right motivation," Nadal said, reports Cincinnati.com.

Meanwhile, Murray has positioned himself as a top favorite to dethrone Djokovic after conquering Wimbledon and winning a second-consecutive Olympic Gold Medal.

All four of Murray's matches against Djokovic this season were final round battles, and while the Scot only managed one victory in their head-to-head matchups this year, his is gradually becoming a legit threat to Djokovic's supreme reign in the tennis scene.

"In the last two years Novak's played in an amazing way. What I have been doing for four months he did all the year. I reached all the Grand Slam finals this year, in 2015 my US Open campaign was very disappointing, so I will try to improve that result," Murray said, reports Tennis World USA.

Djokovic, who is currently nursing a left wrist injury sustained in Rio, is still expected to bounce back from another disappointing loss. The 12-time Grand Slam winner has never lacked the motivation to come back stronger, but doing so could be more difficult this time, with other top players ready to take the spotlight from him.