Malkin is nursing a lower-body injury. He did not play in the team's clinching Game 6 win against the Philadelphia Flyers on Sunday.
Hagelin has an upper-body injury. He left Game 6 with the injury, suffered on a hard hit from Philly forward Claude Giroux.
Game 1 in the Penguins-Capitals series is Thursday at 7 p.m. ET in Washington, D.C.