Mikel joins his Chelsea teammates Michael Essien and Michael Ballack who were omitted by Ghana and Germany respectively due to injury.

Chelsea and Ivory Coast hitman Didier Drogba is also doubtful with a broken elbow.

Mikel, 23, underwent a minor knee operation in May but he believes that he hasn't fully recuperated so far.

"We have dropped Mikel from the squad after he said he did not want to risk his career," a Nigeria spokesman said.

The Super Eagles will replace Mikel with uncapped youngster Brown Ideye, who plies his trade at French outfit Sochaux.