Prague - World number six Marin Cilic and 20th-ranked Sam Querrey have joined the teams for September's inaugural Laver Cup in Prague, the organisers said on their website on Wednesday.
The 28-year-old Cilic, the 2014 US Open champion, will join Team Europe led by Swedish legend Bjorn Borg and also comprising Roger Federer, Rafael Nadal and Dominic Thiem.
"I know how well Roger (Federer) is playing this season so it will be nice to be on the same team in Prague," Cilic said.
"To be representing Team Europe is a huge honour for me."
The 29-year-old Querrey will join Milos Raonic, Jack Sock and John Isner on Team World, captained by John McEnroe.
"Beating four top 20 players to win Acapulco and making the Wimbledon semi-finals have been new highs for me," Querrey said.
"It has been a fun season so far and now I can't wait to be part of the Laver Cup too."
Borg and McEnroe have yet to announce two captain's picks to complete their six-member teams for the new tournament to be played in Prague's O2 Arena on September 22-24.
Named after Rod Laver, the last man to achieve the calendar Grand Slam in 1969, the Laver Cup will be held every year except in an Olympic season, with four matches each day - three in singles, one in doubles.