MANCHESTER: Alexis Sanchez’s miserable spell at Manchester United took another turn for the worse on Friday with manager Jose Mourinho announcing he faces several weeks out with a hamstring injury. The 29-year-old Chilean forward, dropped from the squad for Tuesday’s 1-0 Champions League win over Swiss outfit Young Boys, suffered the injury in training on Thursday. “It is an aggressive muscular injury,” Mourinho said at Friday’s press conference. “He has not had a scan yet but the player is experienced. He knows what injury is. “From my experience, the painful scream and way it happened, it will be a long time. “It is not a little muscular injury that he will be ready in a week or 10 days. “For me and Alexis Sanchez, the grade is different to the one that Lindelof (expected to miss three weeks due to a thigh strain suffered against Crystal Palace last weekend) has and that was not easy.” Sanchez’s came on as a substitute in the league games against Manchester City and Crystal Palace. He last started in the victory at Juventus in the Champions League on November 7. Meanwhile, Mourinho said he is confident Spanish international goalkeeper David de Gea will sign a new deal linking him long-term to Old Trafford. The 28-year-old de Gea’s long-term future at the club has been shrouded in uncertainty, although the club this week did activate an option to extend his current contract by a year, meaning he is now signed up until June 2020.