Orpik will miss Game 3 on Monday, Game 4 on Wednesday and Game 5 on Saturday. He will be eligible to return if the series goes to Game 6 on May 10.
Orpik hit Maatta in the head after the puck was gone four minutes into Game 2 on Saturday and was given a two-minute minor penalty for interference. After a hearing with the NHL's department of player safety, the punishment was far more severe.
Director of player safety Patrick Burke said Sunday in the video announcing the suspension that "this hit is forceful, unacceptably high and excessively late." Orpik's waiting a full second after Maatta released the puck for a shot and his "significant head contact" contributed to the suspension, as did Maatta's injury.
"No player should reasonably expect to be hit at this time and in this manner," Burke said.
Maatta left the game and did not return. Coach Mike Sullivan said the team would probably have an update on Maatta's status on Monday. The 21-year-old Finn has a concussion history dating to his time playing junior hockey.
Pittsburgh coach Mike Sullivan expressed his displeasure with the hit after his team's 2-1 victory in Game 2 on Saturday.
"I thought it was a late hit," Sullivan said. "I thought it was a target to his head. I think it's the type of hit that everyone in hockey is trying to remove from the game."
Orpik didn't have a rap sheet with the NHL, but he does have a reputation for playing on the edge. Although the Capitals did not make Orpik available to speak to reporters after the game, coach Barry Trotz said he spoke with the defenseman about the hit.
Trotz relayed that Orpik thought the puck was coming back to Orpik and that he didn't intend to hit Maatta like that.
"He just finished on a hit," Trotz said. "There's a little size difference, and I think Maatta was leaning over a little bit."
Penguins captain Sidney Crosby said Orpik's hit on Maatta "looked bad right away."
"You can word it how you want," Crosby said. "It didn't look good."
Trotz defended Orpik's character and style of play while acknowledging that whatever the NHL decides, the Capitals will deal with it.
"If you know anything about Brooks, he plays hard, he plays clean," Trotz said. "He's not a dirty player. The Pittsburgh people know that. He plays the game hard but the right way."
With Orpik suspended, the Capitals are without their most physical defenseman and a top penalty-killer. Orpik missed three games of the first-round series against the Philadelphia Flyers after he was concussed on a legal hit from Ryan White on April 18.
The Capitals could turn back to Russian defenseman Dmitry Orlov, who was a healthy scratch in Game 2 after a defensive miscue led to a Penguins goal in Game 1, or to big Mike Weber, a Pittsburgh native they acquired from the Buffalo Sabres at the trade deadline.
Beyond the Maatta hit, Orpik was up to old tricks against his former team Saturday. The Penguins are familiar with Orpik's bruising style. It helped them go to the Stanley Cup finals in 2008 and win it all in 2009.
Asked if Orpik plays any differently with Washington than he did with Pittsburgh, defenseman Kris Letang said, "Uh, no." Later in Game 2, Orpik knocked Letang's helmet off with a glove to the face after a whistle and continued to try to get under players' skin.
"It's part of the game," Letang said of Orpik's post-whistle antics. "I'm not there to judge about that. If they're going to let that go, it's fine. It's going to be equal for every team."