Orpik, suspended three games by the NHL Department of Player Safety, is expected to play in Game 6.
"Olli had a good practice [Monday]," Penguins coach Mike Sullivan said. "He's feeling 100 percent. We'll see how he responds to practice. And he'll be a game-time decision."
Maatta was paired with Trevor Daley Monday on what would be considered the Penguins' second defense pair behind Kris Letang and Brian Dumoulin and ahead of Ian Cole and Ben Lovejoy.
Justin Schultz and Derrick Pouliot were the fourth pair. Pouliot played Games 3 and 4 in Maatta's place. Schultz was in the lineup for Games 4 and 5, though technically he replaced Letang in Game 4, when Letang was suspended, and remained in the lineup for Game 5, with Pouliot coming out.
"It's good to have him back on our side," Letang said of Maatta. "He's really good with the puck, really good at transitioning. He's a really smart player on the rush against really good players. He's got a good stick. He's a good two-way defenseman that can play big minutes for us."
Maatta was averaging 18:42 of ice time per game in the Stanley Cup Playoffs before getting injured at 4:13 of the first period of Game 2. His giveaway in Game 1 led to the first of T.J. Oshie's three goals in Washington's 4-3 win.
"We just want Olli to play within himself and be himself," Sullivan said. "He's been a very good player for us all year. He's been part of our top-four defense corps all year. He's a very smart player. He's positionally sound. As long as he plays within himself and takes what the game gives him and embraces the moment, he's going to be a good player for us."