Novak Djokovic of Serbia celebrates after winning his Men's Singles Final match against Roger Federer of Switzerland at the Wimbledon Tennis Championships in London, July 12, 2015. REUTERS/Stefan Wermuth TPX IMAGES OF THE DAY

Novak Djokovic of Serbia eats some grass off Centre Court after winning his Men's Singles Final match against Roger Federer of Switzerland at the Wimbledon Tennis Championships in London, July 12, 2015. REUTERS/Stefan Wermuth

Serena Williams of the U.S.A lifts the trophy after winning her Women's Final match against Garbine Muguruza of Spain at the Wimbledon Tennis Championships in London, July 11, 2015. REUTERS/Toby Melville

Serena Williams of the U.S.A reacts after winning the first set of her Women's Final match against Garbine Muguruza of Spain at the Wimbledon Tennis Championships in London, July 11, 2015. REUTERS/Suzanne Plunkett 

Roger Federer of Switzerland hits a shot during his Men's Singles Final match against Novak Djokovic of Serbia at the Wimbledon Tennis Championships in London, July 12, 2015. REUTERS/Toby Melville

Saskatchewan Roughriders RB Anthony Allen (26) is tackled by BC Lions LB Solomon Elimimian (56), DL Michael Brooks (90) and DB Josh Johnson (23) during the second half of their CFL football game in Vancouver, British Columbia, July 10, 2015. REUTERS/Ben Nelms TPX IMAGES OF THE DAY

The bull Smoke Show goes after Mike Lee of Fort Worth, Texas after he got bucked off in the Bull Riding event during Championship Sunday at the finals of the Calgary Stampede rodeo in Calgary, Alberta, July 12, 2015. REUTERS/Todd Korol TPX IMAGES OF THE DAY

Novak Djokovic of Serbia throws shoes at fans after he won his Men's Singles Final match against Roger Federer of Switzerland at the Wimbledon Tennis Championships in London, July 12, 2015. REUTERS/Suzanne Plunkett

Ajo Motorsport rider Johann Zarco of France competes to place second in the German Grand Prix Moto2 at the Sachsenring circuit in the eastern town of Hohenstein-Ernstthal, Germany, July 12, 2015. REUTERS/Hannibal Hanschke TPX IMAGES OF THE DAY 

Cricket - England v Australia - Investec Ashes Test Series First Test - SWALEC Stadium, Cardiff, Wales - 11/7/15
England's Ben Stokes bowls as a seagull flies past
Reuters / Philip Brown
Livepic 

Netherlands striker Robin van Persie greets supporters of Turkish soccer club Fenerbahce upon his arrival at Sabiha Gokcan Airport in Istanbul, Turkey, July 12, 2015. Manchester United forward Robin van Persie is expected to sign for Fenerbahce after travelling to Turkey to begin talks with the club. REUTERS/Osman Orsal 

FDJ rider William Bonnet of France receives medical help as he sits on the ground after a fall during the 159,5 km (99 miles) third stage of the 102nd Tour de France cycling race from Anvers to Huy, Belgium, July 6, 2015. REUTERS/Eric Gaillard 

A jockey competes past horses that lost their riders on mud flats during the tideland race (Wadden Race) in Duhnen, Lower Saxony, Germany, July 12, 2015. REUTERS/Fabian Bimmer

German players react during their FIVB Women's Volleyball World Grand Prix 2015 match against Belgium in Sao Paulo, Brazil, July 11, 2015. REUTERS/Paulo Whitaker TPX IMAGES OF THE DAY

The U.S. women's soccer team cheer during a reception at New York City Hall hosted by New York City Mayor Bill de Blasio to celebrate their World Cup final win over Japan on Sunday, in New York, July 10, 2015. Screams and a blizzard of confetti cheered the World Cup winning U.S. women's soccer players as they rolled up New York City's "Canyon of Heroes" on Friday in the first ticker-tape parade honoring a women's sports team. REUTERS/Andrew Kelly TPX IMAGES OF THE DAY

Maria Sharapova of Russia serves during her match against Serena Williams of the U.S.A. at the Wimbledon Tennis Championships in London, July 9, 2015. REUTERS/Toby Melville

Timea Bacsinszky of Switzerland celebrates after winning her match against Monica Niculescu of Romania at the Wimbledon Tennis Championships in London, July 6, 2015. REUTERS/Stefan Wermuth TPX IMAGES OF THE DAY 

Richard Gasquet of France smashes his racket after losing the third set during his match against Nick Kyrgios of Australia at the Wimbledon Tennis Championships in London, July 6, 2015. REUTERS/Henry Browne 

Mo Farah of Britain finishes the 5000 metres men event at the IAAF Diamond League Athletissima athletics meeting at the Pontaise Stadium in Lausanne, Switzerland, July 9, 2015. REUTERS/Denis Balibouse TPX IMAGES OF THE DAY 

Lotto-Jumbo rider Laurens ten Dam of the Netherlands lies on the ground after a fall during the 159,5 km (99 miles) third stage of the 102nd Tour de France cycling race from Anvers to Huy, Belgium, July 6, 2015. REUTERS/Benoit Tessier 

Etixx-Quick Step rider Tony Martin of Germany (C), race leader's yellow jersey, is supported by team mates Julien Vermote of Belgium and Michal Kwiatkowski of Poland after a fall during the 191.5-km (118.9 miles) 6th stage of the 102nd Tour de France cycling race from Abbeville to Le Havre, France, July 9, 2015. REUTERS/Benoit Tessier TPX IMAGES OF THE DAY 

Lucie Safarova of the Czech Republic reacts to breaking serve during her match against Coco Vandeweghe of the U.S.A. at the Wimbledon Tennis Championships in London, July 6, 2015. REUTERS/Stefan Wermuth 

Nick Kyrgios of Australia hugs a ball boy during his match against Richard Gasquet of France at the Wimbledon Tennis Championships in London, July 6, 2015. REUTERS/Henry Browne 

Novak Djokovic of Serbia wipes his face during his match against Kevin Anderson of South Africa at the Wimbledon Tennis Championships in London, July 7, 2015. REUTERS/Suzanne Plunkett 

Richard Gasquet of France falls during his match against Stan Wawrinka of Switzerland at the Wimbledon Tennis Championships in London, July 8, 2015. REUTERS/Stefan Wermuth TPX IMAGES OF THE DAY