Team events are having quite the resurgence on the men's tennis circuit, with three different competitions scheduled in the next four months.
What's still unclear, though, is whether they can all co-exist in the long term.
"Something's got to shake out," John McEnroe acknowledged Thursday, ahead of captaining a six-man world team in the annual Laver Cup event.
The three-day Laver Cup, co-owned by and starring Roger Federer, started in 2017 while the International Tennis Federation sought a new format for the historic but ailing Davis Cup. It pits a team of European stars against a selection of players from the rest of the world.
The revamped Davis Cup arrives in November with 18 nations - though not Federer's Switzerland - playing over seven days in a single city, Madrid, to end the 2019 season.
Another team event launches the 2020 season - the inaugural 24-nation ATP Cup played January 3-12 in Australia.
Then there's the Tokyo Olympics as well, another addition to an already packed schedule.
Federer has committed to playing at the ATP Cup but hasn't made up his mind yet on the Olympics.
He's confident, though, that there is room in the calendar for all three team events.
"Absolutely," Federer said Thursday, at the Europe squad's Laver Cup news conference in Geneva.
"There were places in the past for four different Davis Cup matches," Federer said, recalling the February-April-September-November fixtures he and Stan Wawrinka played to lift the 2014 trophy.
"Now it's less than that" for the three separate team tournaments.
Since Switzerland won its first and only Davis Cup title, Federer has only played a single fixture to gain eligibility for the 2016 Olympics.
Few expect the 38-year-old Federer to fit a Davis Cup comeback into his selective schedule. He would likely get a wild-card exemption for the 2020 Tokyo Olympics, if he decides to play there.
McEnroe noted there was no Olympic tennis for most of his career, during which he committed to the Davis Cup more than most peers.
"Davis Cup was an important part of my life and career, a chance to represent your country," he said, adding that the competition founded in 1900 was only recently "on life support."
Players need an invitation to be part of the Laver Cup, where they get to be around 1960s great Rod Laver and play with or against Federer.
"They've gotten their heart and soul involvement here," McEnroe said, adding the competition "should be something to survive."
The ITF governing body has a 25-year Davis Cup deal with the Kosmos agency, whose investors include Gerard Pique, the celebrated Spain and Barcelona soccer player.