The British bookmaker, whose full name is Sky Betting and Gaming, is offering 9-1 odds that the English striker will still be with his MLS club come Feb. 4 after the next transfer window.
England's Leicester City (5-6) and Queens Park Rangers (1-1) are the favoured Sky Bet destinations for Defoe followed by West Ham (10-1), Liverpool (12-1), Tottenham (16-1), Arsenal (25-1) and Crystal Palace (33-1).
Defoe's future in Toronto has been under speculation since the MLS team turned down a club-record transfer bid for him at the end of the summer transfer window.
Sky Bet says loan deals will count in its wagers.
Toronto, meanwhile, confirmed Friday that Defoe underwent groin surgery earlier this month. The club did not provide further details.
Defoe played in 19 of 34 league games this season, seeing limited action in the second half of the campaign because of the groin problem.