Career
On 27 June 2011, at the age of 17, he signed for Kayserispor for a record transfer fee for Altay of TRY 2.3 million (€1 million). He made his Süper Lig debut in the starting line-up in which Kayserispor were beaten by Antalyaspor with 0–1 final score, on 16 September 2011. Okay was selected for Turkey"s U-20 squad for the 2013 Fédération internationale de football association U-20 World Cup.
He scored "a beautifully judged chip over the stranded from 25 yards (23 m)" to complete the hosts" 2–1 defeat of Australia and progression to the last 16 of the competition.
On 6 November 2015, Yokuşlu was selected for the Turkey national football team to play friendlies against Qatar and Greece respectively. He made his debut as a late sub against Greece in a 0-0 tie.