Athletic Bilbao have revealed that the surgery to remove a cancerous tumour from the testicle of 21-year-old defender Yeray Alvarez "passed without incident".
It was confirmed last week that first-team defender Alvarez had been diagnosed with testicular cancer and would undergo an operation on Tuesday morning to remove the tumour.
The surgery has now taken place and Alvarez will spend the next 24 hours recovering in hospital before being discharged on December 28.
"He was operated on the morning of December 27 at the Hospital de Cruces. An orchiectomy (removal of the affected testicle) has been performed and the surgery has passed without incident," read a statement from the Spanish club.
Alvarez came through the youth system at San Mames, representing the club's second team before earning promotion to the senior set-up ahead of 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.