TORONTO -- Pittsburgh Penguins star centre Sidney Crosby and defenceman Brian Dumoulin have entered the NHL's COVID-19 protocol after testing positive for the virus, the team announced Wednesday.

Crosby is experiencing mild symptoms, while Dumoulin appears asymptomatic, according to the team.

Crosby's positive COVID-19 test comes less than a week after his season debut after missing the team's first seven games recovering from surgery on his left wrist.

"I'm sure he's discouraged. He worked extremely hard to get to this point, and we were all so excited about getting him back in the fold," head coach Mike Sullivan told the team's staff reporter Michelle Crechiolo. “This puts another roadblock in front of it. But we'll control what we can, and we're hopeful that Sid will return soon."

Despite the overwhelming majority of players being vaccinated, the Penguins roster has struggled with the coronavirus this season. Crosby and Dumoulin are the seventh and eighth players on the team to enter the league's COVID-19 protocol since training camp in September.

Defencemen Marcus Pettersson and Chad Ruhwedel went into the protocol on Monday. Forwards Jeff Carter, Jack Guentzel and Zach Aston-Reese, as well as defenceman Kris Letang, also previously tested positive for the virus.

"It's been a little bit discouraging because I know how disciplined our group is, and I feel as an organization we're trying to do everything we can to mitigate the risk, and yet we're still getting it," Sullivan said. "We're trying to do our very best to keep our players and their families as safe as they can. But we're also trying to function through this process as well and trying to win hockey games, and that's how we're going to go about it."

Carter, Guentzel, and Aston-Reese have since returned to game action. Letang returned to practice on Monday.

"I had pretty much all the symptoms. Congestion, headaches, pressure in the forehead, coughing, loss of taste and smell, body aches and pain in the lower back," Letang said. "That lasted between 4-5 days, and after that it was getting better and better every day."

In his lone showing this season, the 34-year-old Crosby had no points and two shots on goal in a 4-2 loss against the New Jersey Devils last Saturday.

With files from The Associated Press