The Bundesliga outfit were reported to have scouted the 17-year-old striker during the Turkey U21 match against Denmark U21.
Ünal scored in the 2-0 win against Denmark in an international friendly.
The 17-year-old made his first senior appearance for the Turkish national side in a competitive game for the Turkish national team against Luxembourg last week.
Ünal has also been closely linked with a move to Premier League giants Chelsea.
Bursaspor head of youth Necmettin Kocaman recently told Radyospor, “Chelsea have made an offer for Enes, however, we hope he will play for our senior team before making such a move.”
The 17-year-old 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.
Ünal striker 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 striker was recently listed in the Guardian as one of the 40 best young talents in world football.