Briere left Tuesday's 4-3 overtime win over the Tampa Bay Lightning after taking a hit in the second period.
An MRI of his stomach and groin area revealed the extent of the injury, said General Manager Paul Holmgren.
"The injury is significant," Holmgren said, "so he's going to be on the shelf for a little while."
Before his latest injury, Briere had missed 14 of the previous 16 games while recovering from abdominal surgery. He has played in only nine games this season.
He has five goals and four assists for nine points with 10 penalty minutes.
The Flyers signed Briere to a free-agent contract last off-season after he accumulated 95 points (32 goals, 63 assists) with the Buffalo Sabres in the 2006-07 season.