Borussia Dortmund sporting director Michael Zorc admits they're following Real Sociedad striker Alex Isak.

The 21-year-old made the switch from Dortmund to Real Sociedad in the summer of 2019, yet some at the San Sebastian club have stated that the buy-back option would only become possible if several conditions were met. It remains to be seen what these conditions are.

Zorc was responding to questions about Erling Haaland potentially leaving Dortmund, which would then leave a hole in the No.9 position. Therefore, Isak's name came up.

"We believe Alex took the right step of going to Real Sociedad," Zorc said.

"At first, he impressed as a substitute, scoring goals. This season he has become a regular starter, and of course we are following him, but we are happy to have Haaland."