wasn't Koivu suppose to play on the fourth line when he comes back??
He didn't come back because his knee wasn't ready. If he would have come back at this time, he would have played on the fourth line because of the team's success and because he wasn't still at 100% in the coordination. Now he had more practice time and he is at 100% so there's no need to start him on the 4th line.
It's a good thing that Perreault watch the game from the pressbox. He's so damn soft and inconsistent. I'm happy they choose Ribeiro instead, because even if he isn't necessarily the most implicated forward, his offensive instincts are better than Perreault.