CHICAGO -- The struggling Pittsburgh Penguins will have to claw their way back into the playoff race without star forward Jake Guentzel.

The team placed Guentzel on injured reserve before Thursday night's game at Chicago with an upper-body injury. Guentzel, whose 52 points are tied with captain Sidney Crosby for the team lead, will miss up to four weeks.

Guentzel did not play the final 10 minutes of a 5-2 loss to Florida on Wednesday night. Head coach Mike Sullivan said afterward that Guentzel was being evaluated.

The setback is the latest blow for reeling Pittsburgh, which entered Thursday riding a three-game losing streak while falling off the pace in the race for one of the wild-card spots in the Eastern Conference.

The Penguins were already playing without injured forwards Noel Acciari, Jansen Harkins and Matt Nieto, who are all on injured reserve.

Pittsburgh recalled forwards Jonathan Gruden, Vinnie Hinostroza and Valtteri Puustinen from their AHL affiliate in Wilkes-Barre/Scranton to fill in.