Though mild-mannered in person, Haggerty is unafraid to make bold moves (if this one fails, his bid for re-election in 2019 certainly will suffer, too). A former tennis industry executive and a former president of the United States Tennis Association, Haggerty was among those who pushed successfully for a roof over Arthur Ashe Stadium at the U.S. Open and for the U.S.T.A.’s vast new complex at Lake Nona in Orlando, Fla.

“Certainly this is a big decision for the I.T.F.,” Haggerty said by telephone from London on Monday. “We know the environment has changed in tennis over the last few years. Players are playing later in their careers. It’s a very physical sport, so I think many factors were taken into account.

“At the same time, if you go back 50 years ago, in Bournemouth they had the first Open tennis event. There had to have been a number of tennis leaders sitting around saying, ‘Jeez, tennis is O.K., do we really need to make this change? What is it going to do to us? Is it good or bad?’ You never know, so that strength of conviction, they had that at the time. They took a risk, but look how tennis has changed. Perhaps in the future, we will look back on this and say the I.T.F. board took such a risk.”

Haggerty also wants a more solid financial base for the I.T.F., which has become the weakest pillar among the sport’s bloated network of governing bodies.

The money could indeed be transformative: Haggerty said the partnership with Kosmos, the investment firm headed by Piqué and backed by the 52-year-old Japanese billionaire Hiroshi Mikitani, would provide more than $20 million in prize money for the players in the final phase each year.

If the $3 billion figure is correct, it would also provide the I.T.F., whose main source of revenue is Davis Cup, with an unheard-of influx of cash to fund its own activities, which include developing the game worldwide and running amateur and lower-level professional circuits. Haggerty also said that national federations would benefit.

If the overhaul is approved, only the seasons ahead will determine who was correct in their assessment: the Kafelnikovs or the Haggertys. But one can understand the lure and the timing. Despite pockets of passion, and a compelling history, Davis Cup is losing traction globally.