Comoros goalkeeper Ali Ahamada has tested negative for Covid-19, and could now start their Africa Cup of Nations last 16 tie against Cameroon on Monday.
However, the 30-year-old faces further tests to see if he is fit to play.
The Indian Ocean islanders had looked like they would face the tournament hosts without a recognised keeper.
Salim Ben Boina was injured in their final group match, and then Ahamada and fellow back-up keeper Moyadh Ousseini both tested positive for coronavirus.
Ahamada and midfielder Yacine Bourhane, who also tested negative on Monday morning, will re-join the squad if they meet requirements set by tournament organisers Confederation of African Football (Caf).
"They are now undergoing various tests, especially physical ones, to return to the competition," Comoros team manager El Hadad Himini said in a statement on Twitter.
"If the tests go well, we will await the findings of the medical commission to see if they can play or not.
"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."
Debutants Comoros, ranked 132nd in the world, face Cameroon at 19:00 GMT and the game will be shown live in the UK on the BBC Sport website, iPlayer and Red Button.
The Coelacanthes had been hit by a coronavirus outbreak affecting players and management ahead of their meeting with the Indomitable Lions, who are five-time Nations Cup winners.
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.
Tournament rules state sides must play if they have 11 fit players, even if no recognised goalkeeper is available.
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.