The contract of Union Berlin striker Taiwo Awoniyi carries a buyout clause.
Signed permanently from Liverpool last summer, Awoniyi is being linked with a return to England.
Newcastle United, West Ham United and Southampton are all in contact with Union Berlin about the Nigeria international's availability.
BILD says the striker's contract carries an affordable €20m escape option.
In 38 games this season, Awoniyi has scored 18 goals.
Need a VPN? Or seeking to switch? Then support Tribal Football by clicking here to sign up with our official partners NordVPN. Not only will you receive the best VPN experience, but also great discounts by signing up via Tribal Football. Thanks for your support!