A Boston Garden security guard holds up a sign asking fans to "Please Mask Up," over concerns with the latest COVID-19 virus spike on Monday in Boston. The virus outbreak has postponed Saturday's hockey game between the Montreal Canadiens and also sidelined many Boston Celtics basketball players after testing positive. (AP photo)

The NBA and its players have agreed to enhanced health and safety protocols through the holiday season in response to rising virus numbers, with additional testing coming and a return to mask usage in many situations.

The upgraded mask rules will be in place “until agreed otherwise by the NBA and Players Association,” according to a memo shared with teams Thursday night and obtained by The Associated Press.

Masks need to be worn again in almost all circumstances during team activities.

The exceptions: during on-court basketball activities for players, and for head coaches during games.

Testing will be increased from Dec. 26 through Jan. 8, the league said. The league also told teams that more requirements and recommendations would be coming in the next few days.

The memo was released on the same day that Russell Westbrook entered the health and safety protocols, joining Milwaukee’s Giannis Antetokounmpo and Brooklyn’s James Harden as past league MVP’s currently sidelined by coronavirus concerns.