The Boston Bruins have added forwards Anton Blidh, Trent Frederic, and goaltender Jeremy Swayman to the NHL's COVID-19 protocol.
Boston has also added a staff member to the league's protocols.
This comes after the team added captain Patrice Bergeron, Brad Marchand and Craig Smith to protocol. Boston now has six players and a staff member in the league's protocols.
The Bruins played the Calgary Flames, who currently have 18 players in protocol, last Saturday.
The Bruins also recalled goalie Kyle Keyser from Providence of the AHL and forward Jesper Froden from the same team on an emergency basis on Thursday.
Keyser, 22, has compiled a 4-5-3 record with a 2.44 goals-against average and .914 save percentage in 12 AHL games with Providence this season.
Froden, 27, has recorded four goals and nine assists for 13 points in 21 AHL games with Providence this season.