Cameroon expect Liverpool defender Joel Matip, West Brom’s Allan Nyom and Schalke’s Eric Maxim Choupo-Moting to arrive at their Africa Cup of Nations training camp on Tuesday.
The trio are among eight Cameroon players called up but refusing to play at the tournament, which starts in Gabon on 14 January.
They could be banned from club football during the competition.
Bournemouth striker Benik Afobe has also withdrawn from DR Congo’s squad.
“We have three players who are due to arrive, notably Allan Nyom and Joel Matip. The third player is Eric Maxim Choupo-Moting,” said team manager Alphonse Tchami.
Choupo-Moting’s German club Schalke 04 said the striker had pulled out of the tournament on Tuesday for “personal reasons”, after initially reporting he had retired from international football.
“The Schalke forward has withdrawn from the 2017 Africa Cup but the 27-year-old will still be available for Cameroon in the future,” the club said in a statement.
“Choupo-Moting’s withdrawal from the tournament is not a permanent one from the ‘Indomitable Lions’ as a whole.”
Cameroon, who are coached by Hugo Broos, have been drawn in Group A with hosts Gabon, Burkina Faso and Guinea-Bissau.
Right-back Nyom told Broos he wanted to stay at West Brom to keep his place in the team.
The other Cameroon players who do not want to play at the competition are Andre Onana (Ajax), Guy N’dy Assembe (Nancy), Maxime Poundje (Bordeaux), Andre-Frank Zambo Anguissa (Marseille) and Ibrahim Amadou (Lille).
“Clubs have to release them and players have to go,” football lawyer David Seligman told BBC World Service. “The only reason they don’t have to go is if they are injured.
“Fifa could sanction both the club and the player. The player could be banned from playing domestic games for the duration of the tournament and the club could be fined.
“The FA would be expected to intervene and they could also face sanction if the player doesn’t go.”