Pittsburgh Penguins defensemen Kris Letang and Zbynek Michalek will sit out Thursday's game against Washington.
Both players are dealing with concussion-like symptoms.
Letang suffered a broken nose Saturday on a hit by Montreal's Max Pacrioretty, who drew a three-game suspension for the blow.
He practiced Monday and Tuesday but was experiencing trouble breathing. He also is suffering from a virus.
Michalek also sat out Tuesday's game after taking a blow to the head in Saturday's game against Montreal. He has been bothered by headaches but was not diagnosed with a concussion.