Late in the 2nd period Thursday night, Koivu returned the favor by levelling Armstrong. Armstrong was very slow getting up and had to go to the bench. I'm guessing he got injured from this check. Looks good on him.
It wasn't from the fight, it was clearly from when Koivu levelled him later on.
Obviously, since it was only after the hit that he was limping. Koivu absolutely hammered him, he stayed on the ground for 3-4 seconds and then returned to his bench shaken up, not sure if he had even returned after that?