Former Real Madrid and Spain captain Iker Casillas was rushed to hospital on Wednesday after suffering a heart attack while training – but is now making a recovery, he has confirmed.
Casillas had been training in preparation for Porto's Primeira Liga home game against Aves at the weekend, although he is now unlikely to play again this season.
The 37-year-old goalkeeper, who made 167 appearances for the Spanish national team, suffered the attack during a morning training session and was taken to hospital where he was diagnosed with "myocardial infarction", Portuguese radio station Renascenca reported.
"Iker Casillas suffered an acute heart attack during this Wednesday's training session," Porto said in a statement on their official website. "The session was quickly halted so medical assistance could be provided to the Porto goalkeeper, who is currently in the CUF Porto Hospital.
"Casillas is OK, stable, and the heart problem has been resolved."
He said: "Everything controlled here, a big scare but with the forces intact. Thank you very much everyone for the messages and the love."
Casillas remains in hospital under observation.
The 37-year-old is one of the most successful football players of all time, having led Spain to the 2010 World Cup win, as well as back-to-back European Championships in 2008 and 2012. His exploits for the national team earned him the nickname 'Saint Iker' and made him one of the best known personalities in Spain.
Born in Mostoles, Madrid, Casillas burst onto the scene when he made his debut for boyhood club Real as a teenager in 1999, having come through the club's ranks.
During his 16-year stint at Real, Casillas won La Liga five times besides lifting the Uefa Champions League trophy on three occasions, in 2000, 2002 and 2014. He also helped win two Copa del Rey titles, two Uefa Super Cups, one Intercontinental Cup and the Fifa World Club Cup.
He is Real’s second all-time appearance maker, having played 725 matches. Only former teammate Raul – at 741 – has played more games for them.
Real wished their former captain a full recovery.
"Real Madrid would like to offer all our support to our beloved captain Iker Casillas. Throughout his professional career, he always overcame the hardest challenges in order to bring glory to our club," the club said in a statement.
"He has taught us to never give up and has shown us numerous times that the best way to win is to remain as strong as possible when times are tough. Real Madrid and all our fans wish him a speedy recovery and send him all our support."
A tweet on the Spain team's official account said: "All the family at the national team and the Spanish football federation are with you Iker Casillas. Get well soon."
Casillas joined Porto on a free transfer in 2015 before helping them win the league title last season. Porto are second in the Primeira Liga this season, two points behind rivals Benfica. With Casillas in goal for most of the season, they have conceded just 19 goals in 31 league matches, eight less than the second best defence.
Last month Casillas played in both legs of the Champions League quarter-final defeat to Liverpool. His contract with Porto was recently extended until the end of the 2019/20 season, with an option for another one-year extension.
The most recent fatal attack came last week, when experienced Burundi international Papy Faty died after collapsing during a league match in eSwatini – formerly Swaziland – the Burundi football federation said on Friday.
The most high-profile recent case was former captain of Fiorentina Davide Astori, who died of a heart attack in his sleep prior to a Serie A match with Udinese in March 2018.
Casillas is married to the television journalist Sara Carbonero, with whom he has two children.