Barca kick off Champions League defense at home to AC Milan

FC Barcelona will make sweeping changes to their starting 11 for the visit of AC Milan to the Camp Nou Stadium in the UEFA Champions League on Tuesday night. The Catalans suffered a setback in their BBVA Primera Liga campaign Saturday night when they surrendered a 2-0 lead away to Real Sociedad to end up drawing 2-2, prompting coach Pep Guardiola to comment they had to learn the lesson from that match. More worrying for Barcelona was the serious muscle injury suffered by winger Alexis Sanchez. Sanchez has an eight inch tear in his left hamstring and tests on Sunday confirmed he will be out of action for at least two months. Guardiola rested key players at the weekend and Andres Iniesta, Leo Messi, Javier Mascherano and Eric Abidal all watched the majority of the game from the substitutes\' bench, along with Carles Puyol. Although Puyol could still be substitute on Tuesday as he looks to put the finishing touches to his return from injury, Messi, Iniesta, Mascherano and Abidal will all be in the side as Barca commence their defense of the title they won last year, when they defeated Manchester United at Wembley. Mascherano and Abidal will almost certainly return in central defense, with Andreu Fontas stepping down and Sergio Busquets moving into midfield, where Thiago Alcantara will be the player to make way. The big question is whether Guardiola will play Iniesta on the left of his attack, or continue with David Villa, who seems to lack the pace to play in a wide role. Milan travel with former Barcelona striker Zlatan Ibrahimovich as their main attraction. The Swedish striker spent one season at the Camp Nou two years ago and performed reasonably well, before being sold last summer. On moving to Milan, Ibrahimovich criticized Guardiola and will be highly motivated against his former companions as will Dutch international Mark van Bommel, another former Barcelona player currently in the Milan side, which also includes former Real Madrid and Manchester City winger, Robinho. AC Milan are Barcelona\'s main rival in a group that also contains Bate Borisav and Viktoria Pilsen and a win in their opening match would set Barcelona on their way, as well as calming alarm bells from last weekend.