The veteran defenceman was forced to leave late in the first period of a 4-1 loss to Toronto after absorbing a David Clarkson hit along the boards. Scuderi struggled to get back on his skates and hobbled as he was helped off the ice.
"We don't have any definitive news," Penguins coach Dan Bylsma said after the game. "Lower body injury."
Scuderi will be re-evaluated in Pittsburgh.
The Penguins already have forwards James Neal and Beau Bennett and goalie Tomas Vokoun on the injured reserve list. On the plus side, Saturday marked the second game for defenceman Kris Letang after a leg injury.
Scuderi, a 34-year-old from Syosset, N.Y., signed a US$13.5-million, four-year contract to rejoin the Pens in July.
He spent the last four seasons with the Los Angeles Kings after playing five-plus seasons with the Penguins from 2003 to 2009.
Scuderi is a workhorse.
Coming into this season, he appeared in 264-consecutive regular-season games dating back to Dec. 7, 2009. He played in every game each of the last three years, and saw action in 71-plus games in each of his seven full NHL seasons.
The six-foot-one, 216-pounder came into this season having played in 515 of a possible 540 regular-season games (95 per cent) since breaking into the league as a full-time player in 2006-07.
The Penguins were able to shift Deryk Engelland back to the blue-line after Scuderi went down. Engelland, who has been playing as a fourth-line forward, fought Frazer McLaren after the Scuderi injury.
Bylsma wasn't sure what happened to his defenceman.
"He just gets hit, shoulder on shoulder," the coach said.
"It's not really clearly evident," he added.
Said captain Sidney Crosby: "From what I heard, he kind of got twisted up."
"I thought we didn't let that bother us too much," Crosby added. "He's obviously a big part of our team but the guys responded well. The fact that we had (Engelland) to go back there and play D helped out. He's a good player, a big part of our team. But that's not something that really hurt us right away.
"I think the third period was something that probably got away from us a little bit."
The loss was the third straight for Pittsburgh (7-4-0), following defeats to the Islanders and Avalanche.
Crosby complimented Engelland on his fight with Frazer McLaren after Scuderi went down.