Knee surgery. Even if he comes back, how effective will he be the rest of the season. A major blow for Chelsea.
http://soccerway.com/news/2007/December/06/chelseas-drogba-facing-weeks-out-with-knee-surgery
http://soccerway.com/news/2007/December/06/chelseas-drogba-facing-weeks-out-with-knee-surgery