The injury will derail the Stuttgart attacker's productive season, having scored seven goals so far in the Bundesliga
The team announced the news on Thursday, revealing that the Samurai Blue regular had received the knock in practice on the previous day.
Okazaki has had a good run of form lately, scoring in three straight February matches and bringing his total to seven this season. Stuttgart are currently in eighth place and remain six points away from a Europa League bid.
With a three-week rest before he can rejoin practice a distinct possibility, Okazaki could potentially be absent from his club's crucial match against current league leaders Dortmund at the end of the month.
Stuttgart also announced that team captain Serdar Tasci will miss this weekend's fixture against Hoffenheim because of a pelvic injury.