The 24-year-old was operated on in Madrid on Friday by specialist surgeon Lasse Lempainen at the Vithas Madrid Aravaca Hospital. The procedure involved an anatomical reconstruction of the origin of the hamstring muscle group following a complex injury.
Real Sociedad confirmed that the operation was completed successfully and without complications, although the club has not provided a timetable for his return.
"ANDER BARRENETXEA: He underwent surgery this morning for his injury in the posterior region of his right thigh. Dr Lasse Lempainen, through open surgery, assessed the complexity of the injury and treated it by performing an anatomical reconstruction of the origin of the hamstring muscles. The procedure was carried out successfully, without complications, at the Vithas Madrid Aravaca University Hospital," the club's medical statement said.
Barrenetxea sustained the injury during last Sunday's match against Rayo Vallecano, shortly after providing the assist for Orri Óskarsson's winning goal. The problem was similar to one he suffered in his left leg in January 2022, when he was forced to spend almost seven months recovering before returning to action.
The winger and Real Sociedad again turned to Lempainen, who previously operated on him for that earlier injury. This time, the procedure was carried out in Madrid rather than requiring a trip to Finland.
The seriousness of the latest setback is a major blow for Barrenetxea, who had been enjoying an encouraging period of form and had earned a return to the Spain squad for the November international fixtures.
His absence also leaves Real Sociedad without one of their attacking options at a time when they are looking to build momentum in LaLiga. The club will prioritise a complete recovery rather than setting an early return date, particularly given the history of problems affecting the winger's hamstrings.
For now, the focus is on rehabilitation after a successful operation, with the possibility of a return before the end of the campaign remaining uncertain.