Despite injuries, Brad Stevens is confident in Celtics roster, but he will make a move if necessary

Despite injuries to key addition Danilo Gallinari and starting center Robert Williams, Celtics president of basketball operations Brad Stevens remains confident in his roster yet is open to adding another key piece.

During the ABCD Hoop Dreams tournament at TD Garden, Stevens told the Globe Williams and Gallinari will have surgery Thursday to repair knee issues. Williams will miss at least a month after requiring an arthroscopic procedure on his surgically repaired left knee. Gallinari will have anterior cruciate ligament surgery about a month after tearing the ligament playing for the Italian National Team.

“Robert’s obviously a short-term thing,” Stevens said. “We’re hopeful that Rob will be just like last time [in May], in the weight room a day later and starting his rehab. It should not take a long time into the season.”