Sunday, October 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

Want more from Front Office Sports
in your search results?

Add Front Office Sports on Google

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.

Download the FOS App

The business of sports, in your pocket.

QR code to download the app

Scan the QR code to get the app now.

Linkedin
Whatsapp
Copy Link
Link Copied
Link Copied

What to Read

Brewers, Rays Make Playoffs, Complicating MLB Labor Fight

The Brewers and Rays both have below-average payrolls.
Cortlandt defeats Pearl River 7-2 in ice hockey action at Bear Mountain Ice Rink in Stony Point on December 16, 2025.

Parents Sue Black Bear Sports Over Youth Hockey Hotel Tactics

The suit seeks at least $5 million in damages.
Tiger Woods of Jupiter Links GC stretches his left leg next to Tom Kim during warms up before match against the Los Angeles Golf Club who won the TGL finals at SoFi Center on March 24, 2026, in Palm Beach Gardens, Florida.
Exclusive

New Funding Doubles TGL Parent Company Valuation to $1B

TMRW is the parent company of indoor golf leagues TGL and WTGL.
Sep 9, 2026; Los Angeles, California, USA; Los Angeles Dodgers two-way player Shohei Ohtani (17) looks on during the first inning against the Cincinnati Reds at Dodger Stadium.

Ohtani Heads to Injured List as Dodgers Aim for Third Title

The two-way phenom is making a rare trip to the injured list.
podcast thumbnail mobile
Front Office Sports Today

A Conversation with Randy Levine on the Yankees’ $2.6B Apollo Deal and the Protect College Sports Act

0:00

Featured Today

Oct 4, 2025; Tempe, AZ, USA; General action during the first period of the game between the Arizona State Sun Devils and the Penn State Nittany Lions at Mullett Arena

How Military-Style Workouts in College Sports Get Dangerous

For elite athletes, high-intensity training can be “very appealing.”
September 6, 2026

Is Carolyn Tisch Blodgett the Future Face of Giants Ownership?

Amid changes at top of Giants ownership, eyes are on Tisch Blodgett.
September 4, 2026

Wild Transfer Window Shows How Premier League Towers Over Soccer

Spending in England vastly outstripped the rest of Europe.
September 3, 2026

Teams Are Spending Millions to Build Luxury Locker Rooms

It’s a recruiting pitch, a retention tool, and a seven-figure line item.
September 1, 2026

High School Football Sidelines Are Clogged With Content Creators

Administrators call these amateur newcomers the “pajama paparazzi.”

Caleb Williams’s Investment Playbook: ‘No Vices’

The Bears QB has put money into sports, tech, and wellness start-ups.
[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.
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.
March 5, 2026

Former NFL Pros Launch PE Firm for Emerging Leagues

Terrence C. Murphy and Reggie Bush are targeting $150 million for their debut fund.
Sponsored

Drew Weatherford’s Bet on the Youth Sports Economy

Drew Weatherford discusses investing across the youth, college and professional levels.
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.
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.