Argentina striker Higuain trained on Tuesday and has been declared fit for the second leg of the last-16 tie at Wembley.
The 30-year-old, who scored twice and missed a penalty in last month's 2-2 draw in Turin, missed the Bianconeri's previous two matches with an ankle injury.
His timely return softens the blow of Mandzukic's absence.
The Croatia international is battling a thigh problem and was not among the 21-man party that departed for London on Tuesday.
Juve travel to Tottenham on the back of an incredible run of form with Allegri's men unbeaten in their last 20 games in all competitions.
Higuain, 30, is the Old Lady's top goalscorer with 20 strikes to his name so far in all competitions.
Juventus' full squad for Spurs clash: Buffon, Pinsoglio, Szczesny, Del Favero, De Sciglio, Chiellini, Benatia, Alex Sandro, Barzagli, Rugani, Lichtsteiner, Pjanic, Khedira, Marchisio, Matuidi, Asamoah, Sturaro, Bentancur, Higuain, Dybala, Costa.