The NBL has been hit with a second cancelled pre-season game in a week due to COVID-19.
Saturday night's NBL Blitz match between Illawarra and Sydney has been called off because of a positive case in the Hawks' ranks.
All Illawarra players and staff are double vaccinated against COVID-19, but the positive case attended a Hawks training session.
It is a major blow to Illawarra's preparations for the upcoming season after their scheduled match against New Zealand on Thursday was cancelled after four members of the Breakers' squad tested positive.
All members of the Hawks are considered close contacts and will need to return a negative test before leaving isolation.
"The coaches and players are obviously disappointed not to have a chance to play in front of their home fans, especially after Thursday's match-up with the Breakers was also cancelled," Hawks president Dorry Kordahi said.
"The safety of our players and coaches is of the utmost importance and we will continue to follow the advice of medical professionals as we assist with the team's return to the court."
The NBL is bracing for fixture disruptions during the 2021-22 season, which is set to get underway in December, because of Western Australia's strict border stance.
But NBL commissioner Jeremy Loeliger is confident all clubs will play their allotted 14 home games this season.