Jayson Tatum’s ruptured Achilles upends Boston’s 2025-26 outlook, forcing Jaylen Brown into a heavier, potentially closing role while the supporting cast must step up. With Porzingis gone to Atlanta and key veterans moved on, Boston’s depth is thinner, making Brown’s efficiency and durability crucial for any playoff push. The Celtics will lean on youth and new pieces to fill the scoring and defense gaps, turning Brown into the focal point of a reshaped offense.

Boston must balance Brown’s expanded role with improved defense and rebounding from newcomers like Chris Boucher and RJ Luis Jr. If the rotation coheres and protect-the-glass effort rises, the Celtics can still contend for a postseason berth, though the path is narrow without a second high-end scorer beside Brown.