Cullen is the only Lumberjack to earn varsity letters in both football and hockey. On the gridiron, Cullen is still NAU's all-time leader in tackles by a defensive back (326). His final three seasons at NAU represent three of the top five single-season tackle seasons recorded by a Lumberjack in the secondary. On the ice, Cullen played in 56 games for NAU. He had 24 points, including six goals and 18 assists.