It kicks off at the Allianz Juventus Stadium on Sunday at 19.45 UK time (18.45 GMT).
The Rossoneri were hoping to get Giroud in the starting XI after he came off the bench during the 3-2 Champions League defeat to Liverpool.
Ibrahimovic is already out of action after rushing his comeback from knee surgery and aggravating his Achilles tendon instead.
However, during his press conference, coach Pioli revealed neither of the veteran forwards would be available.
“Ibrahimovic is not really doing better compared to how he was feeling before the Liverpool game, so he won’t be there against Juventus, and neither will Giroud,” said the tactician.
“Ibra wants to be Superman, but he can’t do that. Giroud developed lumbago after the Liverpool trip.”
— Martin Sartorio (@MartinSa1988) September 18, 2021