The Spanish club, who won the competition under Juande Ramos in both 2005 and 2006, will play the winner of a clash between Montenegrin side Mladost or Slovakian outfit Senica, whose second-round first-leg encounter finished 2-2 on Thursday night.
Italian hopefuls Udinese will visit either Irtysh or Siroki Brijeg. Kazakh club Irtysh hold a 3-2 advantage over Siroki Brijeg, who hail from south-west Bosnia-Herzegovina, while German side Stuttgart face a trip to Zrinski or Botev Plovdiv.
The third-round ties will be played over two legs on August 1 and 8 with clubs including Tottenham, Fiorentina and Feyenoord entering the competition at the following stage.
Vitesse Arnhem represent Holland in the third round and a trip to either Romania, to face Petrolul, or the Faroe Islands to meet Vikingur awaits.
Slask are best-placed to welcome Belgian side Club Brugge to Poland after taking a 4-0 lead against Montenegro's Rudar Pljevlja and FC Zurich of Switzerland are preparing to visit Skonto of Latvia or Slovan Liberec of the Czech Republic.
Ukrainians Metalurg Donetsk will journey west to either Albania or Bosnia-Herzegovina when FK Kukesi and FK Sarajevo resolve their second-leg tie next week.