Sergio Aguero was taken to hospital on Tuesday after fainting in the dressing room at half-time in Argentina's 4-2 defeat by Nigeria in Krasnodar, Russia.
The Manchester City striker had scored to put his side 2-0 up in the first half, but Arsenal's Alex Iwobi found the net twice as Nigeria came back.
The Argentina FA said the 29-year-old had been taken to hospital to "carry out routine studies as a precaution".
They later confirmed that Aguero had been discharged from hospital.
"He is already in the hotel along with the rest of the team," the BBC reported citing an Argentina FA tweet.
In a statement City said he had been cleared by doctors to return to Manchester as planned "after suffering a dizzy spell" during the match.
After the match Argentina manager Jorge Sampaoli said Aguero had "got dizzy and had to leave".
Sampaoli rested Lionel Messi following the 1-0 win over next year’s World Cup hosts Russia on Saturday and it seemed that they could cope without him, reports Reuters.
Ever Banega curled in a free kick, awarded after Nigeria goalkeeper Daniel Akpeyi picked the ball up outside his area, in the 28th minute and Aguero finished off a sweeping counter-attack eight minutes later.
But Kelechi Iheanacho inspired Nigeria’s fightback.
First, he emulated Banega by scoring from a free kick on the stroke of halftime and then set up the equaliser by pulling the ball back for Alex Iwobi to net seven minutes after the re-start.
The Super Eagles took the lead two minutes after that when Brian Idowu sidefooted home from the edge of the area to finish off a counter attack.
A superb second goal by Iwobi completed the comeback in the 73rd minute as he collected the ball, slipped it between Javier Mascherano’s legs and fired past Agustin Marchesin.