The three-day men’s tournament, which will take place from Sept. 21-23 in Chicago’s United Center, pits two elite six-man squads in three singles matches and one doubles each day. The first five members of each team are selected based on their post-Wimbledon ATP singles rankings, with team captains Bjorn Borg and John McEnroe selecting the sixth. “He’s the best doubles player in the world,” McEnroe told reporters of Sock, adding that he had been struggling in singles. “He’s a great team player,” McEnroe said. “I believe that being around a team atmosphere is going to help.” Jack Sock of the US hits a shot against Daniil Medvedev of Russia (not shown) in the Rogers Cup tennis tournament at Aviva Centre. (Reuters) Edmund joins Roger Federer, Alexander Zverev, Grigor Dimitrov, Novak Djokovic and David Goffin on Team Europe. Sock will play alongside Juan Martin del Potro, Kevin Anderson, John Isner, Diego Schwartzman and Nick Kyrgios on Team World. Wimbledon champion Djokovic, who did not play in last year’s Laver Cup, said he was looking forward to the competition’s “refreshing” format. “Laver Cup is a competition that unites us all and it was really unusual to see,” the Serbian said. Team Europe claimed victory in last year’s inaugural Laver Cup, named after Australian tennis great Rod Laver, with Federer beating Australian Kyrgios in the final match. The 2017 tournament was a hit with fans, selling out in a few hours.