With four games called off this week already and more teams dealing with virus-related issues, the NBA and the National Basketball Players Association enacted additional rules Tuesday in the hope of keeping the season going safely.

Among the new policies: for “at least the next two weeks,” the league and union said, players and team staff will have to remain at their residence when in their home markets and prohibited from leaving their hotels or having outside guests when on the road.

Many of the new rules are similar to what existed in the NBA’s restart bubble at Walt Disney World in Central Florida last year.

Orlando’s game in Boston on Wednesday was also called off, the fourth postponement since Sunday and the third involving the Celtics. Boston currently has eight players listed as unavailable because they are on the NBA’s health and safety protocols list.