FC Barcelona will be without the services of Chilean international winger, Alexis Sanchez for between six to eight weeks. Sanchez had to be carried out of Barcelona\'s 2-2 draw away to Real Sociedad after just 31 minutes, suffering a torn hamstring. He suffered a foul from home defender Dani Estrada and fell badly, clutching the back of his right leg and asking for assistance. Barcelona coach Pep Guardiola immediately brought David Villa into the game, while Sanchez was carried off for preliminary tests. The tests show a tear in the muscle and Sanchez will be out of action for between six to eight weeks, missing games such as Tuesday\'s Champions League encounter against AC Milan and a BBVA Primera Liga tie against Osasuna next weekend. He will also miss such important matches as Barcelona\'s visit to Valencia and the visit of Atletico Madrid to the Camp Nou Stadium. Sanchez had helped set Xavi Hernandez up for Barcelona\'s opening goal of the game and his side will miss his pace and aggression over the coming weeks.