Valencia defender Roberto Ayala will undergo a surgery in his right knee after picking up injury during training, the Spanish club said on Saturday. The 32-year-old Argentinean has torn ligaments in his knee on Friday and had to go for the surgery that he underwent in 2004, the club said on their official website. Ayala won't be back to action before the winter break and he will miss two league encounters against Alaves and Real Mallorca. Valencia are in the sixth spot of the Spanish table with 26 points, eight minutes adrift of holders and leaders Barcelona.