By Ewan Murray Barcelona are aiming to restore their nine-point lead at the top of La Liga on Sunday evening when they visit Real Sociedad. Real Madrid’s commanding 4-0 victory over Osasuna on Saturday reduced Barca’s lead to six points at the summit but they will fancy their chances of regaining their impressive buffer over their Clasico rivals when visiting the Reale Arena. Hansi Flick’s side have won seven on the bounce in all competitions and show few signs of surrendering their imperious early season form. With their attack purring and their midfield reinvigorated after a flurry of injuri…