Ünal became the youngest player ever to score in the Süper Lig last season and already has six first team goals for the Green Crocodiles.
The 17-year-old striker has an extraordinary international record, hitting the back of the net 24 times in 25 games for the U16’s and has already been called-up to the U19 as well as the U21 sides.
The striker was also recently listed in the Guardian as one of the 40 best young talents in world football.
Çalhanoğlu was named best young player of the 2013/14 season by leading German football magazine 11 Freunde.
The 21-year-old is regarded as being one of the best set-piece specialists in world football.
Çalhanoğlu has scored ten times and provided eight assists in all competitions for the Bayer this season.