The Chicago Bulls squad has at least one confirmed Covid-19 case.
The first games in the NBA this season have been called off because of the Covid-19 outbreak.
The Pistons and Raptors will not be playing on Tuesday and Thursday, respectively.
The NBA had to delay 31 games last season.
The next three games of the Flames have been called off because of the Covid-19 outbreak.
The NHL said there was a "likelihood of additional positive cases in the coming days" after six players and one staff member entered Covid-19 protocols.
The NHL has had to pause its season three times this season because of an outbreak.
The NBA said 10 Bulls players and "additional staff members" had entered the league's Covid-19 protocols, meaning the franchise was at risk of not being able to field a team.
The players who have contracted the virus are DeMar DeRozan, Matt Thomas, Coby White, Troy Brown Jr., Javonte Green, Ayo Dosunmu, Alize Johnson, and Derrick Jones Jr.
