Alex Ovechkin, Evgeny Kuznetsov, Dmitry Orlov and Ilya Samsonov received the designation on the same day that the league fined the Capitals $100,000 for a violation of COVID-19 safety protocols.
The Capitals are 2-0-2 this season.
According to the league's statement, the Capitals were fined after players were involved in "social interactions among team members who were in close contact and who were not wearing face coverings."
"I regret my choice to spend time together with my teammates in our hotel room and away from the locker room areas," Ovechkin said in a statement. "I will learn from this experience."
Just one week into the season, the NHL has had to deal with its first postponements. The Carolina Hurricanes had their Tuesday game against the Nashville Predators postponed, then five Hurricanes were added to the league's COVID list on Wednesday.
As a result, the team had its games postponed through Saturday. That move erases a home series against the Florida Panthers scheduled for Thursday and Sunday. The Hurricanes' facilities are closed until furhter notice, the league said.
Washington is still scheduled to play Buffalo on Friday.