Crosby left Thursday night's game at Phoenix early in the third period. After the game, a 4-1 loss by the Penguins, he would only say he had "some discomfort."
The injury appeared to be to Crosby's lower body -- even though he was struck in the upper body by a Coyotes player's stick at one point.
Penguins spokesman Frank Buonomo would not elaborate on the injury Friday. Crosby was not available for comment because the team canceled a scheduled practice Friday after landing in St. Louis just before dawn.
"We have a day off today in St. Louis and will practice tomorrow before the game," Buonomo said. Crosby's participation will depend on how he feels on Saturday.
Crosby, the 2006-07 NHL scoring champion and MVP, missed 28 games last season with a high ankle sprain. He hinted after the game this injury isn't as serious.
"It's day to day. It's a little different scenario. I don't quite look at it like [last season's injury]," Crosby said. "But it's not fun."
Despite being hurt, Crosby seemed more concerned after Thursday night's game about the Penguins' poor road trip than he did his injury.
The Penguins are 0-2-1 on a four-city road trip that winds up Saturday night and have lost successive games in regulation for the first time this season. They were beaten 2-1 in San Jose on Tuesday night.
Crosby wouldn't agree with center Jordan Staal's comment the Penguins "aren't buying into the system and working hard."
"I don't think it has anything to do with the system," Crosby said. "I think it has more to do with urgency. It takes more than a system to do that."
Crosby has three goals and 10 assists in 11 games. He is the team's second-leading scorer behind Evgeni Malkin, who has three goals and 13 assists.