VfB Stuttgart have triggered the purchase option for Germany striker Deniz Undav but it remains unclear whether he will be staying at the Bundesliga runners-up, Sky TV reported on Saturday.
Undav played on loan at Stuttgart last term from Premier League side Brighton & Hove Albion, who for their part have an option to buy him back - which would lead to new talks.
The purchase option is for around €20 million ($21.4 million).
Undav, 27, has said he wants to stay in Stuttgart and is said to have agreed personal terms on a contract over three or four years. He scored 19 goals in all competitions for Stuttgart.
The other Stuttgart striker, Serhou Guirassy, has been linked with a move to Borussia Dortmund, who are also said to be after Stuttgart centre back Waldemar Anton.
Bild reported on Saturday that Stuttgart are also close to signing Augsburg's Bosnia striker Ermedin Demirović. The 26-year-old scored 15 Bundesliga goals last term.