The Barcelona coach foresees a tough quarterfinals second leg versus Real Sociedad.
Another Lionel Messi exhibition secures a win for Barça on Basque ground.
The Barcelona coach talked after the victory over the Basque side which made Barça advanced in the Copa del Rey.
Barcelona looks to overcome the one-goal deficit in the second leg against Athletic Club.
Piqué talks about the upcoming Copa del Rey final against Sevilla and comments on the league win.