The news was confirmed by ESPN's Adrian Wojnarowski, who reported that Hauser's agent, Jason Glushon, finalized the deal.

Hauser, who went undrafted out of Virginia before joining the Celtics in 2021, has quickly established himself as one of the most accurate 3-point shooters in the league. This season, he recorded an impressive 42.4% shooting accuracy on 3-pointers, making him a valuable asset for the team.

In addition to his shooting prowess, the 26-year-old forward played nearly every regular season game and even started in 13 games. These contributions further solidified his place within the Celtics' roster and demonstrated his value to the team.

Under the terms of the contract extension, Hauser will remain with the Celtics through the 2028-2029 season. He is set to earn an average annual salary of around $11 million, reflecting his growing importance to the team.

While Hauser's contract may not break records, it does put additional strain on the Celtics' payroll. The team is projected to have one of the most expensive payrolls in NBA history, with a projected $225 million payroll for the upcoming season. This will be accompanied by a hefty $210 million luxury tax penalty.

With the addition of Hauser's extension, the Celtics' projected payroll for the 2025-2026 season reaches $225 million, combined with a similar $210 million luxury tax penalty. This elevates their payroll to the highest in the league for a second consecutive year.

Despite the financial implications, the Celtics have been determined to build a strong roster for the upcoming season. They have already signed long-term extensions with star player Jayson Tatum, securing him for a record-breaking $315 million contract. Additionally, the team secured pivotal guard Derrick White with a $126 million extension.

With a freshly re-signed core and the addition of Sam Hauser's shooting prowess, the Celtics are gearing up for a strong run at a back-to-back championship next season. The team's ambition and commitment to fielding a competitive roster indicate their determination to continue their successful run in the NBA.