Sean Couturier left last night's match against the Pittsburgh Penguins early on after taking a hit and going into the boards. What was initially thought to be a shoulder injury actually turned out to be a rib injury, as Couturier suffered a "costochondral separation."
This injury occurs when your rib tears away from the cartilage that connects it to your breastbone.
With him out for an extended time, expect rookie Morgan Frost to be slotted into the lineup. We'll see how AV adjusts his lineups for Monday's game against the Buffalo Sabres.