The Boston Celtics have secured their core players, including Jayson Tatum, Jaylen Brown, and Derrick White, with substantial contract extensions following their 2023-24 NBA championship win. Tatum's supermax contract, worth around $315 million over five years, underscores his role as a franchise cornerstone. Derrick White, pivotal in their championship run, signed a four-year, $125.9 million extension. Despite being limited by salary cap constraints, the Celtics managed to retain key players and add minor pieces like draft picks Baylor Scheierman and Anton Watson. The team also signed a long-term lease with TD Garden, ensuring stability in their home venue. Heading into the next season, the Celtics have 14 of their 15 roster spots filled, focusing on maintaining flexibility for potential health issues.