Sergio Aguero has undergone medical checks after reports he fell ill during Argentina's 4-2 defeat by Nigeria in a friendly in Krasnodar.
The Manchester City forward apparently fainted at half-time before being taken to a local hospital. He was later released and rejoined the rest of the Argentinian squad.
Aguero started the game and scored in the 36th minute before being withdrawn at half-time during the game, which was played at Krasnodar Stadium in Russia.
The Argentine Football Association said on its Twitter account that the 29-year-old "had a blackout and was taken (to hospital) so routine examinations were made only as a precaution."
Referencing a previous heart problem, Argentinian team doctor Donato Villani told reporters: "He felt bad twice, and with the medical history he has, since he was operated on when he was 15, we wanted to be sure it was nothing.
"We took him to hospital to make sure everything was normal, we prefer to wait to be sure."
Manchester City were keen to play the incident down and have not yet ruled Aguero out of Saturday's trip to Leicester City.
A statement from the club said: "Sergio Aguero has been cleared by doctors to return to Manchester as planned after suffering a dizzy spell during Argentina's 4-2 defeat by Nigeria in Krasnodar today.
"Sergio never lost consciousness, and was taken to hospital for precautionary medical checks. He will be assessed by the club's medical team ahead of this weekend's Premier League trip to Leicester City."
In the match, an Argentina side without Lionel Messi squandered a two-goal lead and slipped to a shock 4-2 defeat.
Ever Banega and Aguero gave Argentina the lead, with Aguero's former Manchester City team-mate Kelechi Iheanacho pulling a goal back for Nigeria just before half-time with a free-kick.
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Arsenal forward Alex Iwobi scored twice and Brian Idowu also found the net for Nigeria in the second half.
Argentina defender Javier Mascherano said: "Playing against a team of such physical strength you pay the price. They walked all over us... and when we tried to get back on the match we couldn't."
Argentina only secured its spot in the next World Cup in the last round of South American qualifiers and has not delivered convincing performances without Messi.