The matches take place in Durban and Nelspruit, South Africa, next week and will apparently have plenty of empty seats.
Durban's semifinal match with Mali Wednesday still had 19,000 tickets available Saturday and Nelspruit had 24,000 unsold seats, officials told the BBC.
The Feb. 10 finals in Johannesburg were nearly sold out but the Confederation of African Football rallied fans to make it to the semis.
"We've got great stars here, the football has been great and we owe it to the continent to make sure the stadiums are full," said CAF Secretary-General Hicham El Amrani.
The CAF was hopeful there would be a late surge in sales once the participants in the Nelspruit match were finalized after the weekend quarterfinals.