Dutch goalkeeper Jasper Cillessen went under the knife on Thursday after tearing a muscle and a tendon in his right quadricep.
According to the club, club doctor Ignacio Muñoz completed the surgery and the keeper is "doing perfectly".
Although Valencia haven't put a timescale on his recovery, sources suggest Cillessen will be out for the next three months to recover.
"Valencia CF goalkeeper Jasper Cillessen has undergone a successful operation this Thursday in Valencia, to treat the muscle and tendon rupture of the anterior rectus of his right quadriceps muscle. The operation was carried out by Dr. Ignacio Muñoz Criado and his team. The player will spend the next 24 hours in hospital before being discharged."