Toulouse defender Cheikh Mbengue has got last minute clearance to play Senegal against Cameroon in an Africa Cup of Nations qualifier this weekend.
Mbengue, a former France under-21 player, can now make his debut for Senegal, where his parents hail from.
Lyon full-back Lamine Gassama is also free to play for the Teranga Lions.
Gassama never played a competitive match for a French junior side and therefore does not need clearance from Fifa to change national allegiances.
Senegal currently top Group E with nine points, five more than both DR Congo and Cameroon - with pointless Mauritius propping up the table.
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.
Football's world governing body 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.
Elsewhere, Montpelier midfielder Younes Belhanda, named in Morocco's squad for Saturday's clash with Algeria, is also ineligible with Fifa saying no application has been received for him.
However, his club team-mate Abdelhamid El Kaoutari can make his Atlas Lions debut after Fifa granted his application for a change in nationality last month.
Morocco host bitter North African rivals Algeria in Group D, the tightest group in qualifying where all four teams have four points.
Football's world governing body added that applications by former England under-21 internationals Victor Moses and Shola Ameobi to play for Nigeria have been received but are still pending.