Iker Casillas has reportedly required ‘surgical intervention’ after suffering a heart attack on Wednesday.
According to Mais Futeobol, Casillas was transferred to the CUF Porto Hospital and operated on immediately.
The 37-year-old is already said to be conscious after surgery and is communicating with medical staff.
Casillas currently holds the Champions League record for most appearances (177), in addition to winning over 20 honours throughout his career.
The star married Spanish TV journalist Sara Carbonero, 35, in 2015 and the couple have two sons, Martin and Lucas.
Casillas is one of the most-decorated footballers on the planet after a glittering playing career.
He came through the ranks at Madrid and went on to become arguably the finest 'keeper ever to grace the hallowed Bernabeu pitch throughout his 16-year stay.
During the highly-successful period, with the majority spent as club captain, he won La Liga five times and also lifted the Champions League trophy on three occasions.
Casillas also counts two Copa del Rey titles, two Uefa Super Cups, one Intercontinental Cup and the Fifa World Club Cup among his accolades.
He played a staggering 725 times, the second most in Madrid's history, before joining Porto on a free transfer in 2015.
And he has continued the success in Portugal by capturing the Primeira Liga and Supertaca Candido de Oliveira crowns to his collection over the past two years.
But undoubtedly his greatest achievement came at international level as he kept guard for the legendary Spanish side throughout their four-year reign as the planet's most-feared football nation.
Casillas was in goal as La Roja claimed back-to-back European Championships in 2008 and 2012, sandwiched between the 2010 World Cup triumph in South Africa.
After making his debut in 2000, he went on to win a national record 167 caps for his nation - making him the joint-most capped male footballer in history.
Now he looks unlikely to play any part in Porto's run-in as they battle Benfica for the title.
Source: onefootball