Barcelona striker Sergio Aguero says he is "always positive" despite reports his heart problem could force him to retire, with Argentina coach Lionel Scaloni still hoping to see the star return to competitive action.
Aguero was handed only his second start for Barca in a Liga clash with Alaves on October 30, but had to be withdrawn early after suffering from chest pains and complaining of dizziness.
He was attended to on the Camp Nou pitch by the club's medical staff before being taken to hospital for cardiological tests.
Barca released a statement shortly afterwards confirming that Aguero will be unavailable for selection for the next three months, with a specialised rehabilitation programme set to be undertaken once doctors have decided on the best approach to take with his condition.
"Sergio Aguero has been subjected to a diagnostic and therapeutic process by Dr Josep Brugada," the statement read.
"He is unavailable for selection and during the next three months the effectiveness of treatment will be evaluated in order to determine his recovery process."
Catalunya Radio has reported that the Argentine, who only moved to Camp Nou from Manchester City over the summer, may have to retire due to a serious health problem.
Aguero has been sidelined by a condition that will initially keep him out for at least three months, but the forward has now come out on social media to say tests of his fitness are ongoing and he is staying upbeat.
Responding to the retirement talk via Twitter, Aguero wrote: "Given the rumors, I can say that I am following the instructions of the club's doctors, doing tests and treatment and checking my progress within 90 days. Always positive."
Argentina manager Scaloni hopes a full recovery can be made by a player that is going through "something no-one deserves", with well wishes from South America being sent to the Barcelona striker on the back of retirement talk surfacing.
Scaloni told reporters when asked if he has been in contact with a man that has 101 caps and 41 goals for Argentina to his name: "Regarding Kun, yes, we've talked and we've sent each other messages.
"Besides him being a player, he is a boy we appreciate a lot.
"We are sad because he is going through something no-one deserves.
"We hope he recovers and could be playing as soon as possible. We send him all our support."
Aguero has said that he is facing a rehabilitation programme in "good spirits", but it remains to be seen whether Manchester City's all-time leading goalscorer and a Copa America winner with Argentina over the summer will ever take to the field again.