Iker Casillas has calmed fears over his health with a message on social media after a heart attack on Wednesday.
Casillas, 37, underwent emergency surgery as messages of support came in from around the footballing world.
Porto released a statement earlier on Wednesday saying Casillas was "stable and his heart problem has been resolved."
And the goalkeeper himself has now posted a message on Twitter with a picture from his hospital bed.
Todo controlado por aquí, un susto grande pero con las fuerzas intactas. Muchísimas gracias a todos por los mensajes y el cariño 😃💪🏼 pic.twitter.com/i3TXsELUGD— Iker Casillas (@IkerCasillas) May 1, 2019
"Everything under control here, a big scare but my forces are intact. Thank you very much for the messages and affection," Casillas said.
Porto president Jorge Nuno Pinto da Costa released a statement on the club's website saying Casillas would require a period of rest, with the goalkeeper already ruled out for the rest of the season.
"The health problem that Iker Casillas suffered today fortunately did not have the consequences that it could have had," the statement read.
"In any case, it requires a hospital stay and a period of rest and inactivity. First of all, I would like to express my solidarity on my behalf and on behalf of FC Porto.
"All of us, managers, coaches, players, all of us who are our everyday companions with the goal of winning, we will have an additional reason to put all our efforts in the conquest of the next victories that he, as we, so much desire.
"Whatever each person does from this moment, he will have to make an extra effort so that he will continue to be the most successful team in the world. Strength Casillas! You are Porto! "
Porto are currently two points back of first-place Benfica, with three league matches remaining.