Central to Gyökeres’s frustrations is a belief that he had an agreement with Sporting president Frederico Varandas to sell him for a certain fee, believed to be around €70 million (£60.4 million, $82 million). Varandas has publicly insisted Gyökeres will not be sold for such a price.

Viktor Gyökeres’ transfer to Arsenal is on the brink of collapse after Sporting CP changed the terms. The Swedish striker was the Gunners’ big bet to end a 21-year Premier League title drought.