Kornet (hamstring) has been ruled out for Friday's game against the Nets, Taylor Snow of the Celtics' official site reports.
Kornet tweaked his hamstring during Wednesday's loss to Golden State and was deemed doubtful before being downgraded to out. The big man's absence could open up an increased role for Jordan Walsh with Neemias Queta starting in the frontcourt while Jaylen Brown (hip) is out. Kornet has averaged 4.9 points and 4.2 rebounds across 18.1 minutes through nine regular-season appearances. His next chance to suit up will come Sunday against Milwaukee.