Both players will sit out Game 4 in Tampa on Wednesday night.
Downie's ban comes as the result of a charge on Penguins defenseman Ben Lovejoy during the first period. He was going to be assessed a minor penalty on the play, but the Penguins scored a goal before the Lightning were able to gain possession of the puck for the whistle to be blown.
"I'm very disappoined in myself," Downie said Tuesday. "I felt like I let the team down."
Defenseman Marc-Andre Bergeron is among the options Lightning coach Guy Boucher is considering as a fill-in for Downie.
Although Lovejoy said he was not hit in the head, NHL senior executive vice president vice president Colin Campbell said in announcing the suspension: "Downie left his feet and launched himself at the head of his opponent and he came from a considerable distance, with speed and force, to deliver the check."Kunitz connected with an elbow to the head of Lightning forward Simon Gagne on a separate play in the first period of what ended up a 3-2 win for the Penguins. They hold a 2-1 lead in the best-of-seven series.
Gagne implied the blow was intentional, but Kunitz insisted it wasn't.
"I had my hearing this morning. Told my side of it. Obviously it looks bad. I never intentionally meant to hurt him. I'm glad that he's OK and was able to finish the game," Kunitz said.
Penguins coach Dan Bylsma said Mike Comrie or Eric Tangradi, both scratches for Game 3, could replace Kunitz for Game 4.