The 20-year-old made 12 Bundesliga appearances for the German side last season and has been told he can go on loan for a year.
That has sparked interest from Liverpool and Southampton, who are both fans of the Turkey international.
Celta Vigo however, according to Bild, are also in the frame to land Mor and they believe they could recruit the prospect ahead of their Premier League rivals.
The Spanish side are promising to give the winger regular first-team football and that may sway him to reject offers from England.