Borussia Dortmund's 19-year-old striker Alexander Isak will move to Spanish top flight outfit Real Sociedad, based in San Sebastián, ahead of the new season.

"We wish Alex Isak every success in Spain and will closely monitor his performances," said BVB sporting director Michael Zorc.

The Swede spent the second half of the season just ended on loan at Dutch club Willem II.

All parties involved have agreed not to disclose the details of the agreement.