Stand-in captain Joseph Yobo will undergo scanning on his ankle after he pulled out with pain from SaturdayÂ´s 1-0 win over Benin Republic in Benguela.
Yobo has only just come out of an injury at the end of last year in time for the African Cup of Nations. But the recurrence could mean he is out of the finals and may be heading back to England. His exit means 2008 Olympic silver-winning defender Onyekachi Apam has a chance to prove self.
Yobo has now played at five African Cup of Nations finals, starting from 2002 in Mali. He was also at the finals in Tunisia in 2004, in Egypt in 2006 and in Ghana two years ago.