The public health unit says about 25 people played at TRIO Sportsplex and Event Centre on Nov. 11 and 15.
It says the players wore masks during the game but not while they were in the change rooms.
Most of the cases were Toronto residents, with some from surrounding areas.
Team sports were allowed in York Region at the time but screening of patrons was required.
The region moved to stricter pandemic restrictions on Nov. 16, prohibiting team sports except for training.