Goalkeeping great Iker Casillas suffers heart attack in training
Casillas, 37, is said to be “out of danger” and conscious but was taken into emergency care at the Hospital CUF Porto after falling unwell during training on Wednesday morning.
His club have issued a statement saying that Casillas is "stable" as messages of support have flooded in for one of the most popular goalkeepers in the game.
Casillas, a modern goalkeeping great, spent most of his hugely successful career at Spanish giants Real Madrid, before moving to Porto in 2015.
He has won a record 167 caps for Spain, and was captain of the 2010 World Cup-winning team.
He is regarded as among the greatest goalkeepers of his generation, and has enjoyed a stellar career during which he has racked up honors including three UEFA Champions League titles.
Along with the World Cup, he also helped Spain to the European Championship title in 2008 and 2012, as part of one of the greatest international teams ever to grace the game.
Despite his advancing years, he recently signed a new contract with Porto which was due to keep him at the club until age 40.
The news of Casillas' shock hospitalization soon filtered through to social media. His club team Porto offered a message of support, sharing an image of the 'keeper with the message 'always together'.
Tennis great and Real Madrid fan Rafael Nadal was also among the first to send hopes of a speedy recovery.
Casillas most recently played in the 2-2 Primeira Liga draw with Rio Ave on Friday, and was preparing with the Porto team for the home game against Aves on Saturday. He has made 42 appearances for the club in all competitions this season.