Novak Djokovic will be joining Rafael Nadal, Roger Federer and Andy Murray to play for Team Europe in the Laver Cup.
The event, which pits six European players against six from Team World over three days, will take place in London between 23 and 25 September.
Felix Auger-Aliassime, Taylor Fritz, and Diego Schwartzman have so far been named in Team World.
"It's the only [event] where you play in a team with guys you're normally competing against," said Djokovic.
"To be joining Rafa, Roger and Andy - three of my biggest all-time rivals - it's going to be a truly unique moment in the history of our sport."
In terms of Grand Slam wins, Nadal has 22, Djokovic 21, Federer 20 and Murray has three.
Team Europe, who are captained by Bjorn Borg, have won the previous four Laver Cup events.
"I don't think I could have imagined having these four icons of the sport on one team together," said Borg, whose former long-time rival John McEnroe captains Team World.
"I know they, like I, appreciate the significance of this moment and will be truly up for it. Each year our goal is to win. With Rafa, Roger, Andy and Novak on the team, I like our chances."