Real Sociedad captain Mikel Oyarzabal would have come back into the side after missing the goalless draw against Getafe through suspension.
However, the forward sustained an ankle injury in Spain's goalless draw with Serbia and has subsequently been ruled out of Saturday's home fixture.
With Oyarzabal sidelined, Imanol Alguacil could be tempted to give Oskarsson the opportunity to lead the line after making his debut in the final game before the international break.
If Oskarsson is given the nod over Umar Sadiq, he will likely be supported in attack by Sheraldo Becker and Japan international Take Kubo, who grabbed a goal for his country in a dominant 7-0 win over China.
In midfield, Martin Zubimendi is expected to be joined by Spain Under-21 international Benat Turrientes and former Manchester City man Sergio Gomez.
With Hamari Traore ruled out through injury, Alguacil will have to decide whether to utilise Jon Aramburu or Alvaro Odriozola on the right side of defence.
On the opposite flank, left-back Javi Lopez is set to make his fourth start of the season, while a centre-back pairing of Jon Pacheco and Igor Zubeldia will offer protection to Alex Remiro.
Ander Barrenetxea has recovered from a fitness issue and could provide an option off the bench, but the hosts will be unable to call upon the services of Arsen Zakharyan and Brais Mendez.
Real Sociedad possible starting lineup: Remiro; Aramburu, Zubeldia, Pacheco, Lopez; Turrientes, Zubimendi, Gomez; Kubo, Becker, Oskarsson