This is the unfortunate fallout from when the Celtics opted to get an upgrade.
The Boston Celtics knew what they were getting into when they traded for Nikola Vucevic. They had just acquired one of the league's most well-rounded offensive centers, whose Achilles heel was his defensive shortcomings. The move was to shore up their frontcourt depth, but unfortunately, his addition to the team meant Luka Garza was firmly out of the rotation.