Everton defender Joseph Yobo was ruled out for two weeks on Wednesday after suffering a hamstring injury against Benin in a CAF Africa Cup of Nations match at the weekend.
"The result of the scan is that Yobo will be out for two weeks. He has rejoined the team, but he is very unlikely to take any further part in the Nations Cup," said Nigeria Football Federation (NFF) official Taiwo Ogunjobi.
Yobo tore his hamstring as he tackled Benin striker Razak Omotoyossi early in the second half of their Group C match in Benguela.
Nice defender Onyekachi Apam replaced Yobo in Wednesday's 3-0 victory over Mozambique, which qualified Nigeria for the quarter-finals of the tournament.