In a statement, the NBA said the Raptors were unable to field the required eight players.
"Because of positive test results and ongoing contact tracing within the Raptors, the team will not have the league-required eight available players to proceed with the scheduled game against the Bulls," the league said in its statement Sunday.
The decision came two days after the Raptors beat the Houston Rockets despite multiple coaches -- including head coach Nick Nurse -- and star forward Pascal Siakam sitting out because of the NBA's health and safety protocols.
It remains unclear whether the Raptors will be able to return to the floor before the All-Star break this weekend. Toronto is scheduled to host the Detroit Pistons on Tuesday before traveling to play the Boston Celtics on Thursday.
Last week, the NBA released its schedule for the second half of the 2020-21 season. Before the team's latest coronavirus issues, the Raptors were scheduled to play 36 games in 67 days.
The NBA has maintained that it wants all 30 teams to play 72 games this season.