A family disagreement over the Celtics‘ rising payroll was behind Wyc Grousbeck’s decision to put the majority stake in the team up for sale, sources tell Josh Kosman and Brian Lewis of The New York Post.

Ninety-year-old Irving Grousbeck controls about 20% of the franchise and is unwilling to absorb the projected financial losses that will be necessary to keep the team in title contention, according to Kosman. After winning the championship in June, Boston handed out several new contracts that will bring the total cost of the roster for the 2025/26 season to about $500MM in salary and tax payments.

“That’s what happens when dad puts in most of the money,” a source told Kosman.

Kosman cites another source close to the sale process who says the team is projected to lose about $80MM this season. That amount will be much higher in the following season when repeater tax penalties become harsher.

The Celtics handed out a record-setting contract to Jaylen Brown last summer, and then topped that with a five-year, $314MM supermax extension for Jayson Tatum in July. Jrue Holiday also received an extension and several players were re-signed, pushing the total team salary north of $225MM and setting up a projected $280MM luxury tax payment.

“Wyc says we’ll spend whatever it takes, but dad wasn’t into losing money,” another source told Kosman, who hears that the team barely broke even last season while winning its 18th NBA title.

The Grousbeck family claimed it was unloading its share of the team for “estate planning purposes” when the surprise announcement was made in early July. Wyc Grousbeck confirmed that stance in a statement to Kosman.

“The Grousbeck family is selling the team for estate and family planning considerations. To say the sale is in any way related to losses is completely incorrect,” he stated. “There has not been a capital call from ownership, or any additional investment of any kind, in the 22 years since Boston Basketball Partners bought the team and we don’t anticipate there being one.”

The NBA is hoping to have the Celtics valued at a record-setting $6 billion for the sale, but there are complications in reaching that figure. Sources tell Kosman that the team’s projected losses and the fact that it doesn’t own TD Garden to provide revenue from other events could make prospective buyers reluctant to bid that high.

The Grousbecks are hoping to sell a 51% stake either later this year or early in 2025 and then continue to run the team until the full sale is completed in 2028.

There has been little movement toward a sale in the two-and-a-half months since the Grousbecks announced that the team was available, according to Adam Himmelsbach of The Boston Globe. Banks helping with the transaction are still reviewing the team’s assets and liabilities to provide an accurate report for interested buyers, which Himmelsbach says is typical in this type of transaction.