Jurgen Klopp has said Liverpool still do not know if they are able to field Joel Matip without breaking FIFA rules.
Matip was omitted from Liverpool's squad for the Premier League draw against Manchester United on Sunday because of a dispute with Cameroon over his international status that threatens to see him miss the FA Cup third round replay against Plymouth on Wednesday.
"There are not a lot of times in my life when I have been in a situation like this, not even a similar situation," Klopp told a prematch news conference. "I don't want to blame anybody but I think our supporters deserve to know about the process we are in.
"In this moment, we are sure we did nothing wrong. We are sure Joel Matip did nothing wrong. He didn't play for Cameroon since 2015. Since he has been here he has not been a Cameroon national player.
"In this moment he is not in the squad of Cameroon, so he cannot play for them, but in this moment we have not a 100 percent guarantee he could play for us. That is the situation."
Matip was named in Cameroon's squad for the ongoing African Nations Cup in Gabon despite Liverpool understanding that he had retired from international football.
The Cameroonian Football Federation had a right to do this under FIFA rules and, with the player having not reported for duty, he could consequently be suspended from club football for the duration of the tournament.
The Cameroon federation issued a statement on Tuesday saying that they would not comment.
"Kindly be advised that FECAFOOT wish not to comment on decision derived from the laws of the game. The laws are impersonal, nondiscriminatory and to be respected as pledged by all actors of the game.
"The decision by Liverpool FC is nor in favour of FECAFOOT neither in disfavour of the player, rather in favour of the law.
"Our focus is the tournament we are competing in at present, which is the most important competition of our continent and among the best globally, as well as the players here present to defend our national colours.
"We shall be available for comments on any other subject at a latter and more relevant time. Thanking you in advance for your understanding."
The situation has surprised Liverpool because the club understood the 25-year-old's decision to retire -- he has not represented Cameroon since September 2015 -- had been respected.
Liverpool have since called on FIFA to step in but so far the world governing body has only highlighted its regulations and left it up to the club to decide whether or not playing him would break the rules.
Klopp added: "I would consider lining him up [against Plymouth] but I don't know if I can. From the sports side it would make sense -- perfect game for him, but I am not sure if I can."
Regarding contact with FIFA, he said: "FIFA told us that this Friday they will decide if they open a case on it or not. I accept rules in life but I think they should always be based on human senses. For me, not a lawyer or a legal person, it is pretty difficult.
"If he had not been injured -- but he was -- then he couldn't have played from Jan. 2. If FIFA opens a case -- and I don't know but I don't think they will because we are sure everything is all right -- then it would be 7-10 days until we get a decision.
"We conceded an offside goal at Man United. That doesn't feel good but I am kind of used to it. In this case it is really hard."
Liverpool travel to Plymouth looking to secure a fourth-round tie with Wolves after being held to a frustrating goalless draw by the League Two side last week.
"They are allowed to defend with all they have," Klopp said. "It is up to us."
Klopp confirmed Loris Karius would replace Simon Mignolet in goal for the game.