The 32-year-old, who is in the fourth year of a five-year, $25 million contract, has two goals, nine assists and eight penalty minutes in 23 games this season. His -1 plus/minus mark represents only the second time in his 10-year career he's in the red in that category.
Martin, who sustained the injury in Pittsburgh's overtime loss to the Bruins on Monday, played only 34 games last season.
The Penguins are already without defenseman Rob Scuderi and they lost fowards Beau Bennett and Tanner Glass in the last week.
The injury could also affect Martin's chances of making the U.S. Olympic team. He made the team in 2010, but did not play because of a broken arm.
Martin has a fractured tibia and will be out approx 4-6 weeks, per coach Bylsma #Pens — Pittsburgh Penguins (@penguins) November 27, 2013