Comoros goalkeeper Ali Ahamada will not be able to play their Africa Cup of Nations last-16 tie against Cameroon on Monday despite testing negative for Covid-19 on the morning of the game.
A media officer from organiser the Confederation of African Football (Caf) told BBC Sport Africa that the 30-year-old had not fulfilled its protocols.
The Indian Ocean islanders are now set to play without a recognised keeper.
Salim Ben Boina (shoulder) and Moyadh Ousseini (Covid-19) are also out.
Ahamada and midfielder Yacine Bourhane, who also tested negative on Monday morning, had hoped to rejoin the Comoros squad for the game against the Indomitable Lions.
But Caf rules state a player who tests positive for coronavirus must isolate for five days before taking another PCR test 48 hours before his side's next match.
The Comoros football federation (FFC) said Ahamada and Ousseini were among several players and management affected by a coronavirus outbreak on Saturday.
Tournament rules state sides must play if they have 11 fit players, even if no recognised goalkeeper is available, and the Coelacanthes will be forced to name an outfield player in goal against Cameroon.
Debutants Comoros, ranked 132nd in the world, face the five-time Nations Cup winners at 19:00 GMT and the game will be shown live in the UK on the BBC Sport website, iPlayer and Red Button.
Comoros were hopeful that Ahamada and Bourhane would be available to return and face the Indomitable Lions, with team manager El Hadad Himini confirming the pair were "undergoing various tests" to return to action.
"If the tests go well, we will await the findings of the medical commission to see if they can play or not," Himini said in a statement posted on Twitter
earlier on Monday.
"We hope they will grant us our rights, just as they did with the other teams. We are waiting now and we hope everything will be better for us."
Defenders Kassim Abdallah and Alexis Souahy, midfielder Nakibou Aboubakari, forward Mohamed M'Changama and coach Amir Abdou also tested positive, with Abdou set to be missing from the dugout.
Comoros are playing at the Nations Cup for the first time in their history and reached the knockout stages after beating Ghana 3-2 and finishing third in Group C.
Both Ahamada and Bourhane featured in the win over the Black Stars.