FILE - In this Dec. 18, 2020, file photo, the Boston Celtics and Brooklyn Nets tip off in front of empty seats at TD Garden to start an NBA preseason basketball game in Boston during the COVID-19 pandemic. The Celtics and the NHL Boston Bruins will be able to start playing in front of a limited number of fans beginning March 22, 2021, under Phase 4 of Massachusetts' reopening plan. (AP Photo/Mary Schwalm, File)