According to Swedish web portal Adtonbladet, the young player that has been branded 'The Next Zlatan Ibrahimovic' decided that it would be best for his development to join Dortmund rather than the star-laden Real Madrid.
With Dortmund star striker Aubameyang poised to leave the club in the summer, Isak could potentially earn a spot in the German team's starting XI as early as next year.
Real Madrid have however reached an agreement with AIK to pay a transfer fee of 10 million euros, so it remains to be seen how the club and the young player will resolve their difference in preferred destinations.