Philippe Coutinho is in "perfect condition" despite having yet to feature for Liverpool this season, with the Brazilian expected to play for his country on Thursday.
The attacking midfielder has missed all five of Liverpool's games so far this term - including both legs of their crucial Champions League play-off round qualifier - with a reported back injury.
The legitimacy of the 25-year-old's problem has long been questioned as he has repeatedly attempted to force a move to Barcelona, who have seen three bids - the latest totalling £118 million - turned down this summer.
Coutinho submitted a transfer request earlier this month, though one which was swiftly rejected by Liverpool as they look to prevent the Catalan giants once again prising away one of their key players.
Recent reports suggested that Coutinho could be reintegrated into the Reds' first-team after the international break.
But he is first expected to take part for his national team in their World Cup qualifiers against Ecuador and Colombia, something which will no doubt fuel the rising levels of anger towards the want-away playmaker from Liverpool supporters.
Coutinho has not trained with Liverpool's first-team squad all month since complaining of a back issue after the club's pre-season participation in the Audi Cup in Germany.
His manager Jürgen Klopp also said last week that a bout of illness had further delayed his return, though Coutinho's medical assessment on international duty has seen him passed fit to represent his nation.
Playmaker set to turn out for Brazil in latest twist of a drawn-out tale
Before joining up with Brazil, Coutinho visited friend and doctor Michael Simoni in his hometown of Rio de Janeiro.
He revealed to ESPN that he didn't "examine" the Reds' No.10 and did "nothing medical" but was rather meeting with him as a friend, having known the player since overseeing his shoulder surgery in 2013.
Simoni, currently the director of health of Fluminense, revealed that he spoke to the Brazil national team's doctor Rodrigo Lasmar and "explained everything" about his fitness.
"He can show up to training normally," Simoni said of Coutinho. "I didn't do a clinical exam, he came to chat, he came to talk to a friend."
The doctor added: "He's a bit anxious about the possibility of changing club. Of course we talked about this possible transfer, about the things that are in his heart right now. His back pains, in my opinion, are explained by this anxiety. Muscular tension normally does that."
Klopp admitted last week that expected Coutinho to go away on international duty, joining Liverpool team-mate Roberto Firmino on his travels.
The German said last Friday: "In this moment he's on our injury list, that hasn't changed. I haven't been in contact yet with the Brazilian FA. The rules are that if they want to see him and check him he will go there. I don't know exactly but I think it will happen. No problem."
Liverpool remain adamant that Barcelona - who have just concluded a deal worth up to a potential £135.5 million for Ousmane Dembélé - will not sign Coutinho, regardless of the size of their offer.
The Merseyside outfit also insist their business will not play any role in the ongoing Coutinho saga, despite the club set to announce a club-record deal for Naby Keïta from RB Leipzig and having submitted an even higher bid for AS Monaco's Thomas Lemar.