Giordano left Thursday's game versus the Coyotes with an apparent head injury, Elliotte Friedman of Sportsnet reports.
Giordano hit the boards hard in the first period and didn't return to the game. The 40-year-old could be set for an absence, which would leave the Maple Leafs short on the blue line. Another update on his status should surface prior to puck drop Saturday versus the Rangers.