"He is suffering a lot from the injury and the pain has become strong," Armin Veh was quoted as saying by BBC Sport.

"There is no way around an operation now."

Nigeria, who were drawn with title holders Egypt in Group C of the African Cup of Nations, will be keeping their fingers crossed that Martins recover in time to take part in the biennial tournament.

The Super Eagles will also face Mozambique and Benin in the tournament that will take place in Angola from January 10 to 31.

Martins, who also played for Inter Milan and Newcastle in his career, scored twice as Nigeria, who missed out on the 2006 World Cup, defeated Kenya 3-2 on November 14 to book a place at next year's South Africa finals.