Boston Celtics v Miami Heat - Game Six
MIAMI, FLORIDA - Derrick White (#9) and Jaylen Brown (#7) of the Boston Celtics react after defeating the Miami Heat 104-103 in game six of the Eastern Conference Finals at Kaseya Center on May 27, 2023, in Miami, Florida. NOTE TO USER: User expressly acknowledges and agrees that, by downloading and or using this photograph, User is consenting to the terms and conditions of the Getty Images License Agreement. Megan Briggs/Getty Images

This week could be the day that sports teams make a splash on players.

The Boston Celtics have made sure to lock Jaylen Brown for five more years after the two sides agreed on a $304 million extension, the richest deal in NBA history so far.

Brown became eligible for the supermax after making the All-NBA Second Team last season.

He will earn $28.5 million for 2023-2024 under his old contract. That amount for yearly salary will double in the next five years. Here's the breakdown of his new contract:

2024-2025: $52,368,085

2025-2026: $56,557,532

2026-2027: $60,746,979

2027-2028: $64,936,425

2028-2029: $69,125,872

The 2016 third-overall draft pick and the Celtics organization were expected to announce a new deal by July 1, but negotiations got stalled, leaving supporters nervous.

However, Boston cleared that they would give Brown the deal he deserved and that only minor details were being ironed out.

More details on Brown's contract

The latest deal for Brown comes fully guaranteed, with no player option and a trade kicker.

The last two items mean Celtics got extra control of the player in his final year.

This is important since Jayson Tatum is also expected to receive a supermax by next year, which will eclipse what Brown just signed today.

Zach Lowe previously speculated that Brown would sign a massive deal with the Celtics, but there is a possibility that he will finish the contract with another team to make sure they will remain on the salary cap.