Wimbledon 2015: Can Rafael Nadal, Roger Federer, Andy Murray Knock Off Champion Novak Djokovic?

No. 1 Novak Djokovic suffered a harrowing four-set loss to a top-form Stan Wawrinka, which denied him glory at Roland Garros nearly a week ago. Djokovic dropped the last three stanzas at the only grand slam left unchecked on his illustrious resume. Recognizing the player’s greatness, the Philippe Chatrier Court spectators still lauded the 28-year-old Serb with a seemingly endless standing ovation.

Tennis spectators are fully aware of Djokovic's determination to win in Paris, but even the best player in the world suffers setbacks. The attention now turns to Wimbledon, where Djokovic is the defending champion. Already the projected favorite by odds makers, the Serbian star owns a 45-8 singles record and two titles at Wimbledon. He could be poised to have a relatively easy time on the much kinder grass surface at the All England Tennis Club in London.

Yet, he’ll have to again run a gauntlet against the "Big Four." No. 2 Roger Federer, owner of the most Wimbledon titles, as well as No. 3 Andy Murray and closest rival No. 10 Rafael Nadal could pose a legitimate challenge for the 28-year-old.

Here's a look at Djokovic and the three tennis superstars:

Roger Federer

This seven-time Wimbledon winner could give Djokovic the most trouble. Federer, 33, owns a 20-19 overall record against Djokovic. In 2014, Djokovic needed five sets and two tiebreakers to upend the Swiss challenger in the 2014 Wimbledon final.

Djokovic has taken two finals from Federer this year: Rome and Indian Wells. But it might be a completely different story on grass. Since 2003, Federer has made the Wimbledon quarterfinals in all but one tournament, and he has not shown many signs of vulnerability on grass.

Here's the stat that really stands out for Federer: 87.3. That his winning percentage on grass. Federer has won 14 grass titles and has a staggering 131-19 record on the surface. He will play at the Gerry Weber Open in Halle, Germany, where he will be in a field that includes Kei Nishikori, Tomas Berdych, and Gael Monfils. Another dominant effort by Federer would be a sign that he is in top form to challenge Djokovic.

Andy Murray

Murray took home the second slam of his career at All England back in 2013, and he beat Djokovic in straight sets to do it. That proved to be the last time the Scot has triumphed over Djokovic, who’s won eight straight, including the French semis in five sets.

But Murray, 28, still represents a significant hurdle with his impressive seven-year run at Wimbledon. He hasn’t slipped up in the early rounds since he first appeared in the slam in 2005 and 2006, and since 2008 he’s at least made the quarters.

At the moment, Murray is inactive but will compete at Queen's Club next week. He won the tournament in 2013 and then went on to take Wimbledon. How he performs against the likes of Wawrinka and Marin Cilic could provide an informative glimpse into his effort at Wimbledon.

Rafael Nadal

These have been trying times for the Spaniard. Nadal saw the French Open slip through his fingers for just the second time in the last 11 years at the hands of Djokovic. With the possibility of revenge playing a role, the former world No. 1 is 23-20 all-time against Djokovic, including a 2-1 mark on grass.

However, Nadal’s only loss to Djokovic on grass was in the 2011 Wimbledon final.

Nadal’s ranking has plummeted of late. After falling to Djokovic in the French quarters in straight sets, Nadal went from No. 7 to No. 10 and his only title all year came in Argentina back in March. He is coming off a solid performance on Friday against Bernard Tomic on grass in Stuttgart. In a relatively weak field, Nadal could boost his confidence by winning the tournament. He could also do himself a favor and provide a strong effort at Queen's Club.

Nadal may need more than just confidence to beat Djokovic, or any of the top players. He has won Wimbledon twice, with his last title coming in 2010.

Conclusion

The upcoming weeks can be very telling, with grass-court tournaments providing a glimpse at potential form. Djokovic has a rich history with each of these competitors, and he’s gotten the best of each lately. But his march to a third Wimbledon title could be rocky. This might be a great opportunity for Murray to build off his impressive play at Roland Garros and upset Djokovic in London.