Barcelona captain Carles Puyol will undergo surgery on his troublesome left knee tomorrow, the Spanish and European champions said.

The 33-year-old defender, who is unavailable for Spain's friendlies against United States and Venezuela next month, missed most of the second half of the season due to injury.

He was left out of the starting 11 for Saturday's 3-1 Champions League final victory over Manchester United but was given a run-out in place of Daniel Alves in the 88th minute.

Doctors Ricard Pruna and Ramon Cugat will brief the media after the operation, Barca said on their website (www.fcbarcelona.cat).