Boston Celtics star Jaylen Brown is eligible for a supermax extension worth $295 million over five years this offseason, but no deal has been agreed upon yet.

ESPN's Brian Windhorst described the negotiations as "fragile," saying that there is interest in both sides, but further talks about certain aspects still need to be done.

"He's eligible for up to 35 percent of the salary cap, but he doesn't have to get that. The Celtics can negotiate on that. They can negotiate on the player option. They can negotiate on several things... There's aspect within the deal you have to negotiate," Windhorst said.

The Celtics also want to ensure all their business is locked before signing Brown to the lucrative extension because he could not be traded for a year for any deal once the ink has been put on paper.

Brown's potential $295 million extension would be the largest contract in NBA history, surpassing reigning Finals MVP Nikola Jokic's $270 million contract with the Denver Nuggets.

Celtics superstar Jayson Tatum has given his stamp of approval for Brown's extension.

Questions loom over Jaylen Brown's extension

Brown's four-year deal, worth $115 million, ends in 2023-24. The 26-year-old forward averaged 26.6 points, 6.9 rebounds, and 3.5 assists, all career-highs during the 2022-23 season.

During the most important game of the year, in Game 7 of the Eastern Conference Finals against the Miami Heat, Brown put up 19 points and 8 rebounds.

However, he shot a horrible 8-of-23 from the field, 1-of-9 from three-point distance, and committed eight turnovers, all catalysts in the Celtics' blowout loss on their home floor.