Just when you want to get comfortable with the Penguins' blue line...

Head coach Dan Bylsma revealed defensemen Kris Letang (right) and Zbynek Michalek were officially diagnosed with concussions today. Both players are out of the lineup indefinitely.

In addition to their injuries, defenseman Deryk Engelland was declared day to day due to an unspecified injury.

With those three dealing with ailments, the Penguins recalled defenseman Alexandre Picard from Wilkes-Barre/Scranton of the AHL for the third time this season. In seven games this season, Picard has no points and is a plus-5.

To make room for Picard on the NHL roster, Letang was placed on injured reserve.

Forward Richard Park is considered a game-time decision due to an unspecified injury.

Forward Jordan Staal is execpted to play tonight despite suffering facial injuries Saturday in Carolina.

(Photo: Jamie Sabau/Getty Images)