Defensemen Brian Dumoulin, Marcus Pettersson and Chad Ruhwedel were also activated and Mike Sullivan will return to coach the Penguins after missing five games while in protocol.
Sullivan said he wasn't sure if the returning players would have limits in ice time.
"We'll see how the game goes, but that's certainly something that we discuss going into this," Sullivan said. "These guys obviously feel strong enough and healthy enough that they're comfortable playing, so we're excited to get them back in the lineup. We'll have to see how the game goes, but that's certainly a discussion we've had."
Crosby has missed five games after testing positive for COVID-19 and being placed in protocol Nov. 3. The center played one game this season (against New Jersey Devils on Oct. 30) after missing the first seven of the season following offseason wrist surgery.
To make room for Crosby, Dumoulin, Pettersson and Ruhwedel on the roster, Pittsburgh assigned forward Drew O'Connor, defensemen Pierre-Olivier Joseph and Juuso Riikola and goalie Louis Domingue to Wilkes-Barre/Scranton of the American Hockey League.
Dumoulin missed five games while in protocol. Ruhwedel and Pettersson each missed three games before returning for a 3-2 shootout win against the Florida Panthers on Thursday. They were placed back in protocol Friday and missed a 6-3 loss at the Ottawa Senators on Saturday.
"'Dumo' did a little bit more because his symptoms weren't as severe as Sid's," Sullivan said. "So Dumo had an opportunity to ride the bike a handful of times. Sid got better toward the end and was able to do a little bit of exercise. And that's just the reality is it affects everybody differently and we're trying to communicate with our players and make sure that we're managing them the right way."
Crosby, Dumoulin, Ruhwedel and Pettersson skated with goalie Tristan Jarry in Pittsburgh on Saturday before joining the Penguins in Washington with Sullivan on Sunday.
Jarry, who is expected to start Sunday, was not in protocol, but did not travel for Pittsburgh's 6-3 loss at the Ottawa Senators on Saturday because Casey DeSmith was scheduled to start and Domingue was called up to dress as the backup.
Sullivan last coached during a 4-2 loss to the Devils on Oct. 30. The Penguins went 2-1-2 with assistant Todd Reirden filling in.
"It was a tough few days, I'll tell you that," Sullivan said. "But I'm feeling a lot better now. It's taken a little while to get over it, but it affects everybody differently and we've had this conversation it seems like a lot with all the different guys that have gotten it here and our experience this year within our own locker room, so it's affected different people different ways.
"For me, those first four or five days were difficult, but fortunately I was able to overcome some of the more severe symptoms and now it's just a matter of just getting the energy level back. But I'm grateful that I'm back and I'm excited about doing what I love to do."
