Sullivan said Malkin, who has a lower-body injury, did not experience a setback, saying it’s “just part of the process.”
Sullivan said it’s possible Malkin can return for Game 3 of the series.
Malkin missed Game 6 of the Penguins’ opening-round win against the Philadelphia Flyers and Game 1 against the Capitals with the injury.
Malkin led the Penguins in goals and points during the regular season. He had three goals and two assists against the Flyers before suffering the injury in Game 5 when he got tangled with the Flyers’ Jori Lehtera.
Winger Carl Hagelin also remains out for the Penguins with an upper-body injury.
The Penguins lead the series against the Capitals 1-0 after rallying for a 3-2 victory in Game 1.