Robert Sanchez’s future as Chelsea’s first-choice goalkeeper has been questioned following his performance against Arsenal.The Spaniard made a number of errors with the ball at his feet and many felt he should have prevented Jurrien Timber’s winner in the Blues’ 2-1 defeat.Chelsea fans had hearts in mouths watching Sanchez on SundayGettyDespite a marked improvement from Sanchez this season, the former Brighton man has never truly convinced Chelsea fans that he is the long-term answer between the sticks.In what is now his third season as the club’s No.1 – his error-strewn display at the Emirates was all-too familiar after the previous two campaigns.“I’ve not seen that performance from Sanchez with the ball at his feet for probably about a year now,” ex-Blues defender Jason Cundy said on our Inside Chelsea show.