The Boston Celtics said starting center Tristan Thompson and backup big men Robert Williams III and Grant Williams will miss Friday night’s game against the Washington Wizards due to COVID-19 health and safety protocols.

According to a report by The Boston Globe, Robert Williams tested positive for the virus and is asymptomatic, and Thompson and Grant Williams are out because of contract tracing. All three are facing a quarantine of at least seven days, the newspaper said.

Boston has four games in the next seven days: Friday in Boston against the Wizards; Sunday at home against the Miami Heat; Tuesday at the Chicago Bulls; and Wednesday at home against the Orlando Magic.

Thompson, 29, is averaging 8.4 points and a team-high 8.5 rebounds in eight starts.

Robert Williams, 23, is averaging 6.8 points and 6.5 rebounds in eight games off the bench.

Grant Williams, 22, is averaging 5.6 points and 3.6 rebounds in eight games off the bench.

All three players participated in the Celtics’ most recent game, a 107-105 road victory against the Miami Heat on Wednesday night.