Ünal joined Genk on a two-year loan from City last week but the Citizens can cut his temporary move short at the end of the season.
The number nine shirt number suggests that Ünal will be playing first-team football over the 2015-16 league campaign for the Belgium side.
The Turkish international scored four goals in 35 appearances for the Green Crocodiles last season, and netted an impressive 181 goals in just 108 matches at youth level.
The 18-year-old striker had joined up with City on their pre-season Australia tour and played against Roma, Melbourne City and Adelaide United.
Ünal cannot play in England next season due to not having a work-permit.
The young striker joined City on a £2 million transfer from Süper Lig outfit Bursaspor last month. Ünal holds the record of being the youngest player to score in the Süper Lig aged just 16 against Galatasaray in 2013.