The former Barcelona forward has made a significant impact since arriving at the Britannia Stadium in July, quickly establishing himself as a fans' favourite with a number of impressive performances.
However, after opening the scoring in Stoke's 4-1 win against Rochdale with a spectacular volley, the 24-year-old went down unchallenged in the first half, prompting concerns over his fitness.
Bojan duly left Spotland on crutches and Stoke confirmed on Tuesday that he has ruptured a cruciate ligament in his left knee and will require surgery.
Stoke manager Mark Hughes said: "It's bitterly disappointing for the club but even more so for Bojan himself as he was making such a big impact on the Premier League and clearly enjoying his football.
"We wish him a speedy recovery."
Bojan's goal at Rochdale was his fifth in all competitions for Stoke, who have won every game he has scored in.
