[VIDEO] Borussia Dortmund welcoming Alexander Isak

Borussia Dortmund have confirmed the signing of Swedish/Eritrean teenage sensation Alexander Isak.

According to the German club, the 17-year-old has signed a long-term contract at Signal Iduna Park, after the Bundesliga side staved off competition from Real Madrid to land the youngster for a reported £8.6million.