The NHL is implementing enhanced protocols through at least Jan. 7, sources told ESPN Wednesday.

The decision comes after the NHL, NHLPA and their doctors held conference calls on Tuesday night and Wednesday afternoon, following a rash of COVID-19 cases across the league.

Under the enhanced protocols -- which NHL players experienced all of last season -- players will be tested daily instead of every third day, according to sources. All team personnel will be required to wear face masks at facilities, meetings will be held virtually, and everyone will be asked to limit all social interactions outside of the hotel, rink or home. The NHL currently has only one player who is not vaccinated, Red Wings forward Tyler Bertuzzi.

The NHL has recommended the booster shot, and many players have already received it. However the league does not intend to mandate a booster shot at this time, sources tell ESPN.

Under the new protocols, players cannot dine indoors on the road. They are also asked to social distance while inside the facilities. COVID-19 testing moves from once every three days to daily, though players do not have to get tested on off days.

More than 130 NHL players have been placed on the COVID-19 protocol list this season, including more than two dozen over the past two days. The Hurricanes' game at the Minnesota Wild Tuesday night was postponed after four additional Carolina players tested positive -- and after the team left two players behind in Vancouver, following additional positive tests.

Meanwhile, the Calgary Flames' season remains on pause until at least Dec. 18 after coach Darryl Sutter and 16 other team members were added to the league's protocols on Wednesday.

The NHL has not considered putting its season on pause, and hopes to be able to finish it on a normal time schedule. The biggest question facing the league now is whether players will go to the Olympics in Beijing in February. NHL players negotiated for Olympic participation in their latest collective bargaining agreement, but the league has an opt-out clause.

The deadline for the NHL to withdraw from the Olympics without penalty is Jan. 10.