The correct plural of the word "Av" is "Avs," not "Av's." The apostrophe signifies possession, not plurality. If you're trying to signify possession as it relates to the Colorado Avalanche, you put the apostrophe at the end of the word, as in "The Avs' legacy of dominance in the regular season will continue to suffer as long as Coach Joel Quenneville is behind the bench."
Avs, not Av's. Get it right.