The Denmark international is likely to be out for an extended period of time after tearing his adductor muscle, while Arturo Vidal is set for a swift return to action.
The Denmark international was given a rare start by Antonio Conte, but was forced off before halftime with what originally appeared to be a groin injury, though tests have confirmed a more serious problem.
"Nicklas Bendtner underwent magnetic resonance imaging and ultrasound that showed a tear in the tendon of the adductor longus left. Prognosis will be better defined after further examinations to which the Danish striker will undergo in the coming days," read a statement on the club's official website.
Bendtner arrived in Turin during the summer on a season-long loan deal from Arsenal, but has failed to settle in Serie A so far.
There was some good news for the Old Lady however, with the statement revealing Arturo Vidal's injury is less serious than originally feared.
"After sustaining bruising in the first half of yesterday's cup game, Arturo Vidal had an MRI scan today which came back negative. The player worked out in the gym as he looks to return to fitness."