Athletic Bilbao president Josu Urrutia has revealed that the Spanish club's 21-year-old defender Yeray Alvarez has testicular cancer and will undergo an operation to remove the tumour next week.

The news was confirmed via a statement from Urrutia on Friday afternoon, with Alvarez remaining "quiet with his family" as he bids to overcome the devastating disease.

"I've seen him well. Peaceful and serene. It is demonstrating what he is, not only in the field, also out. I told him that he is not alone," read part of the statement from the Bilbao president.

Alvarez came through the youth system at San Mames, representing the club's second team before earning promotion to the senior set-up before the start of the 2016-17 campaign.

The defender's La Liga debut arrived in Bilbao's 2-1 victory over Valencia on September 18.