Over more than 100 years of excellence on the rugby field, New Zealand’s All Blacks have created a world-famous brand that transcends their sport.

Now New Zealand Rugby, facing mounting losses, wants to leverage that valuable asset by selling a slice of its commercial operations to U.S. private equity firm Silver Lake. But the proposed deal requires the approval of the players, who fear it will bring a level of commercialization that could do more harm than good to the All Blacks.

It’s a dilemma rippling through all levels of world sport. Owners of teams and leagues are increasingly drawn to the marketing expertise offered by private equity — and the money. For their part, investors see profit potential in fan loyalty and lucrative broadcast contracts.

But the All Blacks aren’t a franchise. They are the national team in the national sport, part of the country’s past and present identity. The players’ creed holds that they don’t own the black jersey, they are custodians of it, honoring its legacy before passing it on, said former captain David Kirk.

"It’s not ours to sell,” said Kirk, now president of the New Zealand Rugby Players’ Association. "How does this generation of administrators have the right to sell 130 years of custodianship? New Zealanders own it, that’s what makes it so valuable.”

Silver Lake has agreed to buy a 12.5% stake in New Zealand Rugby’s commercial operations for NZ$387.5 million. The deal values the business at NZ$3.1 billion ($2.3 billion).

The players’ association has another idea: Take the All Blacks public. They’ve proposed selling 5% of NZR’s commercial operations to New Zealanders via an offering on the local stock market, raising as much as NZ$191 million.

Some professional teams, including the Green Bay Packers and Manchester United, are partially or wholly publicly owned. That model, the players say, is more in keeping with the All Blacks’ history.

The team played a significant role in New Zealand’s coming of age, helping it emerge from the shadow of its colonial past and to embrace the indigenous Maori culture.

In the early 1900s, when touring teams went nearly undefeated through Britain, it stirred pride at home. Maori and Pacific Island players helped bridge racial divides, and the All Blacks today perform the Maori haka — a ceremonial dance or challenge — before every match.

The All Blacks are also one of the few teams that can legitimately claim to be the greatest the world has ever seen across all sports. They have dominated rugby for well over a century, winning 77% of international test matches since their first in 1903.

Despite the on-field success, New Zealand Rugby has posted losses in five of the past six years, showing how difficult it is to fund a champion team from a nation of just 5 million people at the bottom of the world. NZR, which supports rugby at every level around the country, typically only makes a profit when there is a big international tournament like the World Cup, which is held every four years.

Chief executive Mark Robinson says NZR would use the proceeds from the Silver Lake deal to invest in badly underfunded grassroots rugby, ensuring New Zealand continues to produce star players, while tapping the firm’s expertise to better utilize the All Blacks brand as rugby seeks to grow its global audience.

"The research tells us we have 65 million avid fans around the world, another 300 million general fans and then about 900 million people who have an awareness of the All Blacks,” said Robinson, himself a former All Black. "At the moment we don’t have a coordinated, properly resourced and properly skilled approach to be able to monetize that fan base.”

Sport is evolving away from the traditional funding model where a team secures sponsorship, sells broadcast rights and has no real relationship with the consumer. In the digital age, teams are increasingly turning to new forms of technology to help provide a richer, more personalized experience for fans at home and abroad.

NZR sought out a partner that could help navigate those opportunities over the next decade, expanding revenues that have traditionally been restricted by the number of games the All Blacks can play each year. Silver Lake has other sports investments including in mixed martial arts promoter UFC, soccer team Manchester City and Madison Square Garden Sports Co., which owns the New York Knicks and the New York Rangers.

There’s no question about the potential of the All Blacks brand, said Hugo Hensley, Head of Sports Services at Brand Finance in the U.K., comparing it to soccer’s Real Madrid and Manchester United. But risks come if investors tinker with what fans see as the essence of the sport, as with the now-scuppered plans for a European Super League in soccer, he said.

"If owners do not respect the heritage and traditions of a sport, and try to take the organization in a direction without the agreement of the passionate fans, then owners’ plans can backfire and end up massively damaging the strength of their brands,” Hensley said.

Rugby, which is growing in the U.S. and Japan, is drawing new interest from private equity. In March, CVC Capital Partners bought a 14.3% stake in Europe’s Six Nations tournament for £365 million ($518 million). CVC is also in talks with the South African rugby union, and Rugby Australia has said it is considering raising capital through private equity.

NZR is concerned that New Zealand will fall behind its rugby opponents in terms of grasping opportunities to grow if it cannot win the support of the players for the Silver Lake deal. For now, neither side shows any inclination to budge.

"When things get over-exposed, they lose some of their mystique, lose some of what they really stand for,” said Kirk, a former chief executive of Fairfax Media who currently runs an investment firm in Sydney. "Players will start to feel that they’re playing for a commercial entity, not playing for their country.”

Robinson recalled similar hand-wringing for the All Blacks when rugby turned professional in 1995.

"Some people said this is going to be the end of the game, we’re going to lose our values, we’re going to lose our soul, this is going to ruin the legacy of the All Blacks,” he said. "Fast forward 25 years, it’s only enhanced the All Blacks legacy.”