The 33-year-old Argentine player was forced to leave the match, minutes after receiving first aid at the Camp Nou stadium, where he was seen placing his hand on his chest.
Aguero was immediately taken to hospital in an ambulance, for heart checks as a precaution.
Barcelona, who signed the player last summer from Manchester City, said on Twitter, “Aguero reported chest pain and was taken to hospital for heart checks.”
The English club sent a message of support to its former player, saying: “Everyone in Manchester City wishes you a speedy recovery, Aguero. We are with you.”
The scene brought to mind the tragedy of Danish midfielder Christian Eriksen, who suffered a heart attack during a match in the European Championship last summer and fell to the ground in a terrible moment.
And on Friday, Inter Milan said in a statement that Eriksen, 29, would not be able to play in Italy this season, expressing his readiness to sell the player.
Eriksen recovered after saving his life on the field with the help of his colleagues and medical staff, before being taken to a nearby hospital where he was treated with a pacemaker implantation.
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