Soccer's governing body FIFA said on Thursday it had opened disciplinary proceedings against Liberia over an unnamed player who took part in the African Group J tie against Angola on Sept. 7.
Angola won 4-1 and the outcome of the group will not be affected as they finished five points behind winners Senegal. Liberia were bottom on four points.
"Senegal will advance to round three regardless of the result of the disciplinary proceedings, having finished four points clear of Uganda at the top," said FIFA in a statement.
Eight African World Cup qualifiers have been affected by teams fielding ineligible players and the offenders have forfeited the matches on each occasion, with a 3-0 win handed to their opponents.
Last week Cape Verde lost their place in the playoff round of the qualifying competition because they fielded defender Fernando Varela in a 2-0 victory over Tunisia when he should have been suspended.
Tunisia were awarded a 3-0 win, putting them top of the group ahead of Cape Verde.