• Loading stock data...
Saturday, April 4, 2026

Former MLB CFO Jumps to PE, Says Teams Are Undervalued

Jonathan Mariner joins Mark Cuban and other partners with 24 years experience in MLB and aims to find investment opps in the big four U.S. men’s leagues.

Jonathan Mariner
Front Office Sports

Another veteran pro sports executive has jumped on the private equity train. 

Former MLB CFO and EVP Jonathan Mariner has joined Harbinger Sports Partners, a $750 million fund that launched in May, aimed at taking minority stakes in teams in the four major U.S. sports leagues. Harbinger’s co-founders are former Mercedes-Benz USA CEO Steve Cannon and Shark Tank guest judge and Atlanta Falcons LP Rashaun Williams. Mariner will be a general partner along with billionaire Mavericks part owner Mark Cuban, who joined in May.

Mariner was CFO at MLB from 2002–2014, Mariner manned the CFO role for MLB as team sale prices rose from $96 million for the Royals in 2000 (later sold again in 2019 for $1 billion) to $2 billion for the Dodgers just 12 years later. Before he was CFO of the league, Mariner was CFO of the Miami Marlins.

Even with the growth of franchise values in baseball, valuations still sit on average below most NFL and NBA teams. But Mariner sees this as an opportunity for Harbinger to see larger returns in baseball.

“I actually think Major League Baseball has, from an investor perspective, one of the more interesting opportunities,” Mariner told Front Office Sports on Tuesday. “When you look at the more recent valuations, in football and in basketball, there’s some pretty frothy numbers out there, all justified based on some of the things they’ve been able to accomplish in media deals. We think that if baseball can accomplish what it’s trying to do, in terms of its business model components, we think that valuations will improve over time.” 

MLB’s current media deal with FOX and TBS is up in 2028, with ESPN opting out of its $550 million agreement after 2025

The NFL opened its doors to private equity ownership last summer, but has stricter rules than its peer leagues, allowing just 10% PE ownership. MLB, the NBA, and the NHL allow teams to sell up to 30% to PE funds.  The Giants, under majority owner Charles B. Johnson, sold a 10% stake to private equity in March. 

“Given franchise values, I think it really requires other sources of capital to sustain the kind of prices that are being asked for,” Mariner said on the latest episode of Portfolio Players. “So it was inevitable, I think, that you would have to get to that point. If a franchise is going for three, four, five billion dollars, it’s hard to find a person who’s gonna write a check for, let’s say, half of that… so it almost comes down to having to spread out the cap table in order to make these transactions viable.”

Mariner points to baseball’s ongoing CBA negotiations, with the current deal expiring on December 1, 2026, as a key focal point of Harbinger’s investment strategy.

“You almost always have to look at collective bargaining as a fundamental investment principle,” Mariner said. “The most important cost component of an operation is labor. It’s usually somewhere around 50% of your revenue. And so no matter what type of investment you’re looking to engage in, you need to look at the labor situation. The beauty of a collective bargaining agreement is it gives you stability over a defined period of time. I think one of the reasons the NFL has been able to enjoy such prosperity is that it’s been able to have long periods of labor peace, and I think that’s what baseball is trying to accomplish next.”

With more than a year to go before the expiration date, MLB and MLBPA appear to be at an impasse, each holding firm to its agenda with a possible lockout. While CBA uncertainty could hypothetically create lower get-in prices, stability is crucial for prospective franchise investors, Mariner said.

Investing in international sports is not part of Harbinger’s current strategy, but Mariner said it is not out of the question down the road.

Linkedin
Whatsapp
Copy Link
Link Copied
Link Copied

What to Read

Caleb Williams’s Investment Playbook: ‘No Vices’

The Bears QB has put money into sports, tech, and wellness startups.
Aug 23, 2025; Phoenix, Arizona, USA; A general view of the MLB logo before the start of a game between the Cincinnati Reds and Arizona Diamondbacks at Chase Field.

MLB Sets 2026 Draft Slot Values, Could See First $10M Bonus

Bonus values in the upcoming event reach unprecedented levels.
Sponsored

Baseball Is Back: MLB Opening Day Prices Soar

MLB Opening Day ticket prices are at record highs. TickPick data breaks down demand, pricing trends, and where fans are paying the most.

MLB’s Deals With Netflix and NBC Off to Strong Ratings Start

The audience figure formed part of a big opening week for the league. 

Featured Today

‘The Sonics Never Died’: The Long Afterlife of Seattle NBA Merch

Inside “the largest team shop for a team that doesn’t exist.” 
Mar 27, 2026; Washington, DC, USA;UConn Huskies forward Tarris Reed Jr. (5) dunks the ball against the Michigan State Spartans in the second half during a Sweet Sixteen game of the East Regional of the men's 2026 NCAA Tournament at Capital One Arena
March 28, 2026

March Madness Coaches Debate ‘Blueblood’ in NIL Era

The term’s meaning was up for debate at men’s March Madness.
Maxime Vachier Lagrave
March 25, 2026

The Planet’s Best Chess Players Are Having Their LIV Golf Moment

Chess’s most prestigious tournament is battling a splashy Saudi event.
Beau Brune/LSU
March 22, 2026

College Athletic Departments Are Becoming Media Companies

“There’s only so many tickets you can sell, but content is infinite.”
Reggie Bush speaks on unionizing college football players during the Rose Bowl Hall of Fame induction ceremony at the University Club of Pasadena in Pasadena, Calif. Tuesday, Dec. 31, 2024.

Former NFL Pros Launch PE Firm for Emerging Leagues

Terrence C. Murphy and Reggie Bush are targeting $150 million for their debut fund.
Dec 30, 2025; Los Angeles, California, USA; Los Angeles Lakers guard Luka Doncic (77) reacts after scoring a basket against the Detroit Pistons during the second half at Crypto.com Arena
January 4, 2026

Pro Team Valuations Are Set to Keep Climbing in 2026

Asset scarcity and increasing media-rights deals underpin soaring valuations.
[Subscription Customers Only] Jul 13, 2025; East Rutherford, New Jersey, USA; Chelsea FC midfielder Cole Palmer (10) celebrates winning the final of the 2025 FIFA Club World Cup at MetLife Stadium
February 21, 2026

Soccer’s ‘Crown Jewels’ Are Devouring Smaller Clubs

Mega conglomerates are feeding a big business machine. Fans are furious.
Sponsored

Baseball Is Back: MLB Opening Day Prices Soar

MLB Opening Day ticket prices are at record highs. TickPick data breaks down demand, pricing trends, and where fans are paying the most.
December 27, 2025

‘Why Not the Dodgers?’: How Billie Jean King Became an LA Owner

“Getting involved with the Dodgers literally changed our lives,” Ilana Kloss says.
December 23, 2025

Ben Simmons Buys a Sport Fishing Team

“I think I can really help this league grow,” Simmons told FOS.
Jacksonville Jumbo Shrimp mascot Scampi waves to fans during Opening Day baseball against the Gwinnett Stripers on March 29, 2024.
December 17, 2025

Private Equity Dives Further Into Minor League Baseball

Seven MiLB teams have changed hands in the last week.
December 14, 2025

How Pickleball Became One Massive Private Equity Rollup

Pickleball roads lead back to billionaire Tom Dundon.