Knee-knack rules Jankovic out of World Cup
Belgrade's b92 website reported on Wednesday that Jankovic, who returned to the international fold in a 3-0 friendly win over Algeria two weeks ago, faced arthroscopic surgery of his meniscus and up to six months on the sidelines.
The attacking midfielder, who was out for six months after tearing ligaments in the same knee last September, sustained the injury while playing for Genoa against Inter Milan.
Jankovic's absence leaves CSKA Moscow's Milos Krasic as the only natural right winger in coach Radomir Antic's squad.
Serbia are in Group D with Germany, Ghana and Australia.