Penguins' center Sidney Crosby will sit out tonight's game against Boston at Mellon Arena because of a sore groin.

He strained the muscle during the Penguins' 5-3 victory in Philadelphia Monday.

Crosby is the NHL's fourth-leading scorer, with 10 goals and 20 assists in 19 games.

The Penguins recalled forward Erik Christensen from their farm team in Wilkes-Barre. They also placed defenseman Eric Cairns on injured reserve because of post-concussion symptoms.