On November 10, 2008, Kostopoulos was suspended for three games for a hit on Toronto Maple Leafs defenceman Mike Van Ryn during the game between the teams on November 8. He was given a boarding major penalty and ejected from the game. Kostopoulos also forfeited US-$33,000 in pay. Kostopoulos responded about the incident by saying," First and foremost, I sincerely regret the injuries suffered by Mike Van Ryn...this is an unfortunate turn of events. I was just trying to get in on the forecheck and get the puck. I didn't anticipate him turning and couldn't stop. I was trying to finish my check and obviously it did not end up well. I never intend on injuring another player. I feel bad. I hope he is going to be all right and resume playing as quickly as possible." NHL disciplinarian Colin Campbell said in announcing the suspension that while Van Ryn was not in a defenceless position, his injuries—including a concussion—were significant enough to warrant suspending Kostopoulos.