Stephen Craigan and Steven Davis have been ruled out by groin injuries, Kyle Lafferty has a foot injury and George McCartney is out with an ankle problem.
Calderon and Davis had both been starting for the Raptors, but they do have Kyle Lowry waiting in the wings at point guard and likely see Gay's scoring punch as the key to vaulting back into the discussion in a mediocre conference.
Steve Davis, Grant McCann, Sammy Clingan and Damien Johnson is the likely combination in midfield, with Kyle Lafferty set to partner David Healy in attack.