The 23-year-old left-back, who joined Sevilla from Espanyol last summer, was told in early January to stop all physical activity for the time being due to a heart condition.

Sanchez has not played since and after consulting a heart specialist in Hamburg he has decided to undergo a "complicated" operation in the near future.

Sanchez said on his club's website: "Dr Sievers has explained the risks involved in having such an important operation, because it's a complicated surgery, but he made it clear that the risks are few compared to the possible benefits that could come about if I have the operation.

"There is a good chance that I could be able to continue my career as a footballer if everything goes how we want."

In 2007, Sevilla's midfielder Antonio Puerta died after collapsing on the pitch due to a cardiac arrest.