The 34-year-old captain was sidelined for three months earlier this year with knee trouble and Barca confirmed he is now expected to be out for six weeks.\"After tests were conducted it was decided he would have arthroscopic surgery on 12 May,\" the club said.Spain\'s first game of Euro 2012 is against Italy on 10 JuneVicente Del Bosque, who coaches reigning European champions Spain, will announce a provisional squad on 15 May, which will be whittled down to a final squad on 27 May.Puyol experienced discomfort in his knee during Saturday\'s La Liga home victory over Espanyol.He will miss Barca\'s final game of the La Liga season at Real Betis and Pep Guardiola\'s last game as coach, the Copa del Rey final on 25 May against Athletic Bilbao.The powerful defender has been a reliable presence in the Spanish back line for more than a decade and has made 99 appearances for the world and European champions, scoring the winning goal in Spain\'s 1-0 semi-final victory against Germany at the 2010 World Cup.