Andy Murray enters tournament weeks after he retired at Paris Olympics
Last year, Novak Djokovic entered the All-Star Celebrity match at the Ryder Cup. Weeks after winning a record 24th Grand Slam title at the US Open, he was part of Colin Montgomerie's winning team at the Marco Simone Golf & Country Club course. "I was very nervous but I did pretty well in the end," the Serb said at the time.