Liverpool - Liverpool manager Jurgen Klopp expressed his frustration on Sunday that FIFA has failed to make a swift decision about the eligibility of defender Joel Matip.
Matip withdrew himself from consideration for future selection for Cameroon's national team in September 2015, but his country tried to call him up for the African Nations Cup that started this month.
Although Cameroon finalized its squad for the tournament more than a week ago, without Matip in it, Liverpool says the Cameroon Football Federation has failed to confirm he can play for the club during the African Nations Cup.
The Premier League team has sought clarification from FIFA about the issue, but hasn't been given a decision by world soccer's governing body and did not feel it could take the chance on playing Matip against Manchester United on Sunday. He was therefore withdrawn from selection for a game that finished 1-1 at Old Trafford.
"We, the club, did everything we had to do to make this clear but until now we could not get the response we need to be 100% sure that he can play," Klopp said.
"It's pretty difficult and pretty frustrating, to be honest. He's been in training for five days and would have been in the squad, 100%, maybe on the pitch today, so I don't think it's fair. But we cannot do more and are still waiting on the decision. We could not take the risk."
Liverpool believes Matip has followed all the correct procedures and considers he should be available for selection during a busy period for the club, which is playing Premier League, FA Cup and League fixtures this month.
"We need to get an answer as quickly as possible because on Wednesday we have the next game (an FA Cup third-round replay at Plymouth) and then another game and another game. We cannot wait forever," Klopp said.
"It is public now, we have this problem and we are not the only team with this problem."
Fellow Premier League club West Brom has faced a similar situation with defender Allan Nyom, who has not played in the team's last two matches because it has not had similar clarification from FIFA.
FIFA has the power to ban players it feels have not correctly acceded to the request of their national association.