Sam Cassell joined Joe Mazzulla's coaching staff in the summer of 2023. Both he and Charles Lee added some veteran experience next to the sophomore head coach. Cassell and Lee both helped oversee a dominant season for the Boston Celtics, leading to a franchise 18th championship. Lee has since left to become the head coach of the Charlotte Hornets, while Cassell has stepped up to be Mazzulla's lead assistant.
During a recent interview with Celtics Wire's Justin Quinn, which was part of him promoting his deal with Zenni Optical, Jrue Holiday discussed the impact that Cassell has made on the Celtics.