Wenger gives Ozil future update
The Spanish champions have not won in San Sebastian since 2007 and needed a Lionel Messi strike to earn a point in their league visit in November.
They will get a chance to end that winless run of eight matches on January 17, though, before the return leg at Camp Nou a week later.
Real Madrid begin their tie with Celta Vigo at the Santiago Bernabeu as Zinedine Zidane’s side’s hunt for the treble continues.
The leaders made it a record 40 games unbeaten as they battled back to earn a 3-3 draw in the second leg of the last round against Sevilla on Thursday - eclipsing Barcelona’s previous best of 39.
Real’s city rivals Atletico Madrid are also into the latter stages of this year’s competition after beating Las Palmas 4-3 on aggregate.
They will meet Eibar in the last eight, while second division Alcorcon will face Alaves.
Copa del Rey draw in full:
Real Sociedad v Barcelona Alcorcon v Alaves Atletico Madrid v Eibar Real Madrid v Celta Vigo
