The 31-year-old forward is considered day to day with an upper-body injury that kept him out of practice Tuesday. Defenseman Kris Letang, who missed practice because of a maintenance day, is expected to play.
RELATED: [Complete Penguins vs. Flyers series coverage]
Pittsburgh leads the best-of-7 series 2-1. Hornqvist has three points (one goal, two assists) in the three games after having 49 (29 goals, 20 assists) in 70 regular-season games.
Forward Dominik Simon took Hornqvist's place at first-line right wing with center Sidney Crosby and left wing Jake Guentzel on Tuesday. Simon, who had 12 points (four goals, eight assists) in 33 games this season, has been a healthy scratch the first three games of the series.
"Opportunity presents itself," Penguins coach Mike Sullivan said. "So guys are going to have to step up. They're going to get the opportunity to step up, and I think they're excited about it."
Sullivan would not say when the injury to Hornqvist occurred. It's unclear how the Penguins will compensate for his absence on the top power-play unit, where he is the net-front presence. Guentzel could move from the second unit to take his place.
"[Hornqvist] isn't an easy guy to replace," Sullivan said. "He's a unique player for us, and he brings a lot. So I think we're just going to have to, by committee, we're going to have to pick up the pieces and make sure that the opportunities that are given to others that [Hornqvist] normally fills, they're going to get a great opportunity to help this team win a game.
"We believe we have the personnel to do it. We think we have depth at the forward position and this is one of the reasons why. This is what makes our team competitive."
