The £15.4million striker was forced off at half-time during Saturday’s 1-0 win over Southampton after experiencing pain his knee and scans have revealed he damaged his anterior cruciate ligament.
Kalajdzic, who joined Wolves last week from Stuttgart, will see a specialist on Monday to determine the next course of action.
A club statement read: “We now need to support Sasa in his recovery and further updates will follow.”
The 25-year-old Austrian had been signed to provide some much-needed support for Raul Jimenez, the latter of whom missed the win over Southampton due to injury troubles of his own.
Jimenez had been named on the bench but was withdrawn during the warm-up after experiencing what Wolves boss Bruno Lage described as “chronic fatigue”.
A club statement explained: “Raul’s pre-season was interrupted by a knee injury which means that he is still building his resilience and his ability to recover quickly during periods of match congestion.
“It was felt that his body needed a few more days to recover after he felt a pain in his groin during the warm up and we did not want to put him at increased risk of injury.”