Going from an undrafted player to a Norris Trophy candidate, Girardi has transformed into a top-pair defenseman. An adept shot-blocker with acute defensive awareness, he is able to get himself out of trouble in his own end by moving the puck.
A native of Welland, Ontario, Girardi broke in as a 16-year-old with Barrie of the Ontario Hockey League in 2000-01 and helped it reach the OHL Finals in 2001-02. During the 2002-03 season, Girardi was traded to Guelph, where was an alternate captain. A year later he scored two goals and 19 points in the OHL Playoffs and helped Guelph win the championship.