Roger Federer and Novak Djokovic have taken to social media to congratulate retired wheelchair tennis star Shingo Kunieda on his decorated career.Kunieda, the winner of 28 Grand Slam titles and three Paralympic gold medals in the men's wheelchair singles, announced his retirement Sunday at age 38 while at the top of the world rankings."What an incredible career," Federer said on his Instagram account. "It has been a privilege to watch you play and see you leave such an incredible mark on wheelchair tennis. Welcome to the retirement club."Djokovic, who is in Melbourne in his bid to win the A…READ FULL ARTICLE
