Marcus Pettersson and Chad Ruhwedel entered NHL COVID-19 protocol Sunday.
The defensemen joined top-pair defenseman
Kris Letang
, who has missed four games since entering protocol Oct. 23.
Pettersson has scored four points (one goal, three assists) in eight games. Ruhwedel does not have a point in eight games.
Defenseman
Pierre-Olivier Joseph
was recalled from Wilkes-Barre/Scranton of the American Hockey League and could make his season debut against the Philadelphia Flyers at home Thursday.
Pettersson and Ruhwedel are the fifth and sixth Penguins to enter protocol this season. First-line left wing Jake Guentzel missed one game, a 6-2 win to open the regular season against the Tampa Bay Lightning on Oct 12, and forward
Zach Aston-Reese
did not play the first two games.
Center Jeff Carter entered protocol Oct. 21, two days before Letang, and missed three games before returning in a 4-2 loss to the New Jersey Devils on Saturday.
The Penguins are also without forwards
Evgeni Malkin
and Bryan Rust. Malkin, Pittsburgh's second-line center, is expected to be out until at least December after having knee surgery June 4. Rust, normally the first-line right wing, is week to week with a lower-body injury. -- Wes Crosby