ORLANDO — The biggest boost to the National Women’s Soccer League this winter came not through a player signing, TV campaign or expansion announcement.

It landed with an invaluable pop from across the Pacific with photos of tennis superstar Naomi Osaka wearing the gear of an NWSL team in late January. It was a sign not only of her support of fellow female athletes but of her financial investment in the North Carolina Courage.

“Proud to have you join our boardroom!” NWSL Commissioner Lisa Baird tweeted in reaction to a photo of Osaka sporting a blue Courage jersey and red cap. “Women betting on women.”

Since its founding in 2012 — the third effort at women’s pro soccer in the United States — the NWSL has fielded popular players from the top-ranked U.S. national team and many standouts from abroad.

In the past seven months, it has also bolstered its business by recruiting high-profile team investors, including women from a range of fields.

It began last summer when Angel City FC, a 2022 expansion team based in Los Angeles, introduced a glittering list of owners. Among the dozens were Williams; actors Natalie Portman, Jennifer Garner and Jessica Chastain; and former soccer stars Mia Hamm and Abby Wambach.

Then in late January, the Courage announced Osaka had purchased a stake in the Raleigh organization.

Last week, the Washington Spirit got into the act by introducing more than 30 new investors, mostly from D.C. circles. They included daughters of U.S. presidents (Chelsea Clinton and Jenna Bush Hager), a former Senate majority leader (Thomas A. Daschle), Olympians (Dominique Dawes and Briana Scurry) and prominent civic and business figures.

“I feel like women’s soccer is one of the most exciting sports ever, so it’s super exciting to watch,” Williams told reporters in Australia. “They’re so amazing, and it’s really awesome to be a part of supporting other women athletes.”

None of the teams have disclosed how much the new investors have contributed. Angel City is different from the others because it is an expansion team with no prior backers. The league’s entry fee is an estimated $2 million.

For marquee investors, the NWSL is an opportunity to promote sisterhood and women’s sports.

“It’s just an incredible kind of culture shift if we can bring more attention and light and celebration of these incredible athletes,” Portman said last year.

Osaka teamed with Courage owner Stephen Malik, who has owned the 2018-19 champions for four years.

“Far beyond just being a team owner,” Osaka said, “it’s an investment in amazing women who are role models and leaders in their fields and inspirations to all young female athletes.”

The new D.C. investors were enlisted by managing partner Steve Baldwin — a local tech executive who bought a majority stake from founder Bill Lynch before the 2019 season — and business executive Y. Michele Kang, who joined last year.

Baldwin said the newcomers are not part of a marketing trick. “They’re investing their money, their time and their expertise,” he said.

NWSL investment by famous figures, sports business consultant David Carter said, is more for the cause than the financial windfall.

“Licensing your name and reputation to what you deem to be a worthy case is always noble, and doing so has taken on added importance of late,” said Carter, principal at The Sports Business Group and associate professor at the University of Southern California’s Marshall School of Business.

“For most that choose to invest in leagues such as the NWSL, they’re seeking a return on their personal beliefs and objectives at least as much as they are their financial investment, which is relatively modest.”

That does not mean such investment won’t help grow the league.

Sean Clemens, a principal and director at the Park Lane sports investment firm in Santa Monica, Calif., said: “Sometimes investors can set the tone in building an asset and generating momentum. … It’s bringing a lot of cachet, so not only can they bring a lot of appreciation to look forward to, but they can bring more attention to the league.”

As an upstart, the NWSL has dealt with its share of disappointments.

Multiple teams have disbanded or moved, crowds have been relatively small in most markets, and TV exposure was limited until recent years. The U.S. Soccer Federation, the sport’s national governing body, continues to subsidize the salaries of top American players.

The outlook, though, appears to be brightening.

Last year, Olympique Lyonnais, which operates the strongest women’s team in Europe, became majority owner of the Seattle-Tacoma franchise, now known as OL Reign. Louisville will debut in April, increasing the franchise count to 10.

Next year, Sacramento is scheduled to join Angel City as expansion outfits.

The league strengthened its video presence last year by partnering with CBS Sports and Twitch, a live-streaming platform. It has also welcomed additional local and national sponsors, such as Budweiser and Google.

The popularity of the 2019 World Cup in France helped lift average attendance that year to 7,337, a 72 percent increase since 2013.

The previous women’s leagues, the Women’s United Soccer Association and Women’s Professional Soccer, each lasted three years.

Daschle, who retired from the Senate in 2005 and now heads a public policy firm on K Street, began consulting with Baldwin a few years ago on growing the soccer organization. But as the team and league evolved, Daschle said, he and his wife, Linda, decided “we’d like to be more than just consultants; we’d like to be investors.”

The addition of prominent individuals, Daschle said, will “elevate the team and the sport in ways that only they can. They each have their own profile, their own visibility, and bringing those reputations and visibility to the sport is immensely helpful.”

Williams (whose investment also includes a stake for her 3-year-old daughter, Alexis Olympia Ohanian Jr.) and Osaka demonstrated that during the Australian Open, appearing in NWSL team gear or talking about their soccer investment.

Angel City plans to use its Hollywood presence to further its branding in the lead-up to its expansion season, much like Los Angeles FC did in its first MLS season in 2018 with investors Will Ferrell and Magic Johnson, among others. Angel City will play at LAFC’s downtown stadium.

“The women’s national soccer team has been arguably the most captivating women’s sport or organization in this country for the last 20 to 22 years,” Clemens said. “Hopefully this move [by the NWSL] is the start of something big and flourishes over the long term.”

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