Galchenyuk took line rushes at second-line left wing with Nick Bjugstad at center, where Malkin normally plays when healthy. Dumoulin returned to his defense pair with Kris Letang.
"It's good to be back around the guys," Dumoulin said. "It was good to get a full practice in with a lot of guys out there. It was fun being with the team again."
Malkin was injured in the Penguins' second game this season, a 7-2 win against the Columbus Blue Jackets on Oct. 5. Midway through the second period, he clipped skates with Letang before tripping and tumbling into the boards.
"I thought [Malkin] looked really strong on the ice," Sullivan said. "He's been skating with Ty [Hennes], our skills coach. His conditioning level looked pretty good. We'll see where he goes after today."
Pittsburgh has won six of 10 games and is averaging 3.1 goals without Malkin.
"He's obviously a big part of our success here," forward Patric Hornqvist said. "He's one of the best players in the world. We really miss him out there. It would be nice to see him come back pretty soon."
Malkin started his 14th NHL season with a goal in a 3-1 season-opening loss to the Buffalo Sabres on Oct. 3. After that game, he said the Penguins weren't hungry enough.
In nearly four weeks since, Malkin said he's seen Pittsburgh play with more urgency.
"I remember, we talk about how we have a good team," Malkin said. "We have a great four lines. Yeah, we don't play great in the first game, but in the second and third, and the last three games, the team played amazing. ... We work hard. We have skilled guys, a good power-play unit.
"We need to work hard the whole game. Now you see, we have like five good lines. Young guys, they do a great job. They help so much. I hope when I'm back, keep winning. I need to help team, give more skill and more energy."
Malkin had 72 points (21 goals, 51 assists) in 68 games last season, led the Penguins with 89 penalty minutes, and was an NHL career-low minus-25. When training camp opened Sept. 13, he said that led him to train more vigorously than usual during the offseason.
After practice, Malkin said he was frustrated with being injured two games into the season.
"I miss the ice so much," Malkin said. "I don't play in a long time, like all summer. Missed the last three weeks. It's a little bit hard mentally. I try to stay positive. I try to focus, do my best and work hard."