Andy Roddick of the United States speaks to the media during a press conference announcing his retirement during Day Four of the 2012 US Open. (Photo by Michael Heiman/Getty Images)
2012 US Open - Day 4
Serena Williams of the United States reacts against Maria Jose Martinez Sanchez of Spain during their women's singles second-round match on Day Four of the 2012 US Open. (Photo by Al Bello/Getty Images)
2012 US Open - Day 4
Serena Williams of the US reacts on court against Maria Jose Martinez Sanchez from Spain during their 2012 US Open match. (Photo credit should read TIMOTHY A. CLARY/AFP/GettyImages)
2012 US Open - Day 4
Tatjana Malek of Germany reacts during her women's singles second-round match against Sloane Stephens of the United States on Day Four of the 2012 US Open. (Photo by Mike Stobe/Getty Images for USTA)
2012 US Open - Day 4
Martin Klizan of Slovakia reacts during his match with Jo-Wilfried Tsonga of France during thier men's match at the 2012 US Open. (Photo credit should read DON EMMERT/AFP/GettyImages)
2012 US Open - Day 4
Sloane Stephens of the United States returns a shot during her women's singles second-round match against Tatjana Malek of Germany on Day Four of the 2012 US Open. (Photo by Cameron Spencer/Getty Images)
2012 US Open - Day 4
Ayumi Morita of Japan returns a shot during her women's singles second-round match against Tsvetana Pironkova of Bulgaria on Day Four of the 2012 US Open. (Photo by Elsa/Getty Images)
2012 US Open - Day 4
Philipp Petzschner of Germany returns a shot during his men's singles second-round match against Nicolas Almagro of Spain during Day Four of the 2012 US Open. (Photo by Matthew Stockman/Getty Images)
2012 US Open - Day 4
Nicolas Almagro of Spain returns a shot against Philipp Petzschner of Germany during their men's singles second-round match on Day Four of the 2012 US Open. (Photo by Cameron Spencer/Getty Images)
2012 US Open - Day 4
Stefan Kendal Gordy, better known by his stage name Redfoo from the band LMFAO, and tennis player Ayaka Okuno from Japan watch the match of Nikolay Davydenko of Russia against Mardy Fish of the U.S. during their 2012 US Open match. (Photo credit should read TIMOTHY A. CLARY/AFP/GettyImages)
2012 US Open - Day 4
Jo-Wilfried Tsonga of France jumps over the net while trying to return a shot against Martin Klizan of Slovakia during their men's singles second-round match on Day Four of the 2012 US Open. (Photo by Cameron Spencer/Getty Images)
2012 US Open - Day 4
Kei Nishikori of Japan reacts after defeating Tim Smyczek of the United States during their men's singles second-round match on Day Four of the 2012 US Open. (Photo by Dan Istitene/Getty Images)
2012 US Open - Day 4
Jelena Jankovic of Serbia returns a shot against Lara Arruabarrena-Vecino of Spain during their women's singles second-round match on Day Four of the 2012 US Open. (Photo by Elsa/Getty Images)
2012 US Open - Day 4
Ana Ivanovic of Serbia celebrates after winning her match against Sofia Arvidsson of Sweden during their 2012 US Open match. (Photo credit should read TIMOTHY A. CLARY/AFP/GettyImages)
2012 US Open - Day 4
Maria Kirilenko of Russia returns a shot against Greta Arn of Hungary during Day Four of the 2012 US Open. (Photo by Cameron Spencer/Getty Images)
