Grousbeck’s Big Bet: Can Owner’s Spending Keep Celtics on Top?

The Celtics, now owners of an NBA-record 18 championships, are already the clear favorite to repeat next year as champions. But doing so will likely come with heavy financial costs and will test the mettle of team owner Wyc Grousbeck (above, holding trophy), who quietly has become one of the most influential executives across the sports industry.

Operating without a megastar such as the Lakers’ LeBron James or the Warriors’ Stephen Curry, the Celtics in some ways have become an East Coast version of Golden State, traditionally one of the NBA’s top-spending teams and one that used financial muscle to help build a modern-day dynasty. Boston’s 2023–24 payroll of $184 million ranked fourth, according to Spotrac—trailing only the Warriors, Clippers, and Suns—and stood above the league’s luxury tax threshold of $165.3 million. That, in turn, set up a luxury tax bill for the Celtics of nearly $40 million. 

As is often the case for newly minted champions, though, maintaining current levels is not an option in Boston, and next year’s figures will be higher across the board. The NBA luxury tax threshold is rising to $171.3 million. Already, though, the Celtics have more than $192 million in contract obligations for the 2024–25 season. 

Further bills are also likely coming due as forward Jayson Tatum is reportedly eligible for a supermax contract extension that would pay him $315 million over five years. Combined with teammate Jaylen Brown’s five-year, $304 million deal signed last summer, setting a league record, the pair could be set to receive $480 million between 2025 and ’29.

Paying the luxury tax again next season will establish the Celtics as repeat offenders of going over the NBA’s soft salary cap, and further penalties kick in once a team pays the tax in three of the prior four seasons.

The Man Signing the Checks

Grousbeck, however, has shown not only a willingness to dig deep in support of the Celtics, but also has been one of the most active investors in recent years across the industry. Primarily through the investment firm he cofounded, Causeway Media Partners, Grousbeck has invested in companies such as ticketing operator SeatGeek, streaming outlet FloSports, and internet radio provider TuneIn, among many others. 

The owner also is a backer of the John Henry–led Strategic Sports Group that completed an investment deal worth up to $3 billion with the PGA Tour to create a new for-profit commercial entity, PGA Tour Enterprises. 

That’s not the only tie for Grousbeck to his Boston-area pro team ownership colleagues. Grousbeck also collaborated last year with Henry’s key partner, Fenway Sports Group chairman and fellow Strategic Sports Group investor Tom Werner, to develop a situation comedy inspired by Grousbeck’s life. The show, Extended Family, debuted in December on NBC and starred Jon Cryer and Donald Faison, with former Celtics stars such as Paul Pierce and Rick Fox holding smaller roles. Thirteen episodes aired, but the network did not pick up Extended Family for a second season.