Yet, in a stunning turn of events, the Celtics mounted a remarkable 26-point comeback to secure a 112-107 win. The catalyst for the turnaround? Head coach Joe Mazzulla's candid halftime message to his team.

Boston Celtics head coach Joe Mazzulla loves to push his players, and his halftime challenge sparked the team's comeback win over the 76ers on Sunday.

The Celtics and Cavaliers split the first two games of their season series, with each team winning on its home floor. Boston was missing White and Jaylen Brown in their most recent meeting, a 115-111 Cavs victory on Dec. 1.

Boston Celtics guard Jaden Springer smiles after hitting a three-point shot during the second half of an NBA basketball game against the Los Angeles Clippers, Wednesday, Jan. 22, 2025, in Inglewood, Calif. (AP Photo/Mark J. Terrill) AP

The Boston Celtics surely won't be the NBA's most active team leading up to Thursday's 3 p.m. ET trade deadline. However, they can't just sit out

When the Celtics were in the thick of their rebuild, with piles of assets and big dreams, they were connected to just about every big star who became available on the trade market.