Hartnell broke his foot in the third game last season and had a subpar year after he returned.
Holmgren also said that center Vinny Lecavalier would miss about a week with a lower-body injury. He was injured when he collided with a Coyotes player near the goal line Friday and hobbled to the bench.
Neither injury involved a fracture or needs surgery, Holmgren said.
The Flyers will not pursue a trade, Holmgren said, adding he will give Michael Raffl and Tye McGinn a chance to show they belong. Both were recalled from the AHL Adirondack Phantoms on Saturday.
Raffl, 24, who played in a lower-level Sweden league last season, made his NHL debut. The 6-foot, 190-pounder had a goal and two assists with the Phantoms, while McGinn had a goal. Both played in two games with Adirondack this season.
"I'm anxious to see how Michael and Tye do," Holmgren said. "Tye's been here before and he played some good games for us last year, and I'm really excited to see Michael play. I know it's only been two games, but he's been very good down there."
McGinn, 23, was on the top line Saturday, with Claude Giroux and Jake Voracek. Raffl and Wayne Simmonds were wingers on the second line, centered by Brayden Schenn.
"We'll see how it goes," Holmgren said. "They both were OK in camp; they're both big bodies. I think they can play a little bit higher up in the lineup and hopefully they can give us a little life and enthusiasm."
The Flyers need some life. They started the night 1-4 and had scored just six goals.
Breakaways. Raffl committed an early hooking penalty and Todd Bertuzzi scored 25 seconds later to give Detroit a 1-0 lead. . . . Defenseman Erik Gustafsson, paired with Kimmo Timonen, played in his first game this season, replacing Andrej Meszaros. Luke Schenn went back to being paired with Mark Streit.