 He registered 24 points (three goals and 21 assists) and was named to the Central Collegiate Hockey Association (CCHA) All-Rookie Team in his freshman year.The following season for Petry saw a drop in performance, as he was held to a total of 14 points (two goals and 12 assists).He achieved a significant improvement to his game for his junior year at Michigan State, however, as he finished third overall in team scoring and first as a defenseman, collecting 29 points (four goals and 25 assists).