The 22-year-old winger will join Besiktas on a temporary basis, with the option to make the move permanent at the end of the season if certain criteria are met, according to Voetbalzone. Poku's absence from Bayer Leverkusen's training session on Tuesday night had already suggested that a transfer was in the works, with German newspaper BILD reporting that he had also said goodbye to his teammates. Voetbalzone reports that a fee of around €25 million is involved in the deal, which would see Bayer Leverkusen make a significant profit on the player they signed from AZ for €10 million last summer. Poku had signed a contract with Bayer Leverkusen until 2030.