Explained: The Swedish striker is determined to leave St James’ Park and Fifa’s amendments to article 17 give him an exit route next summer that would potentially cost Newcastle millions of pounds

You've probably seen coverage of the Alexander Isak transfer saga, but you are probably far less familiar with a little-known FIFA rule called Article 17. It could be the key to unlocking Isak's future.

This appeared to be a cryptic reference from Isak to the prospect of talks being held over a new contract last summer. Isak, however, still had four years to run on his deal at the time and discussions were ultimately postponed due to the club's Profit and Sustainability (PSR) concerns.