Mbengue, who was capped by France at under-21 level, will make his debut for Senegal, where his parents hail from, in Saturday’s key match in Cameroon.
However, Guinea could find themselves in trouble if they use former Swiss junior international Thierno Bah, who has been called up for their match against Madagascar on Sunday.
FIFA said they had not received any application for the player to switch his international allegiance.
Burkina Faso, who face Namibia on Saturday in a Group F qualifier, could also face sanctions if they choose to play 35-year-old Brazilian-born goalkeeper Nilson or Cameroon-born defender Herve Zengue.
Zengue made his debut for the Burkinabe against FIFA regulations in March and they intend using Nilson, from Portuguese club Vitoria Guimaraes, as their new goalkeeper.
They risk forfeiting the points, however, because FIFA rules are clear on the subject.
FIFA say players must be either born in the country they represent, or have had a parent or grandparent born there or have served an uninterrupted residential qualification period of five years.
Zengue, born in Cameroon, plays in Russia for Terek Grozny and has no ties with Burkina Faso but was invited to play for them when they beat Namibia 4-0 in their last group game in March.
“If a member association fields a player who is not eligible, the member association will lose the match by forfeit and will have to pay a fine,” a FIFA spokesman said in response to a Reuters e-mail on Saturday.