Liverpool and West Ham United are eyeing Hamburg striker Son Heung-Min.
The South Korea international, 20, is being linked with a £9 million move to Anfield, while he is also being watched by West Ham.
The youngster struck twice in HSV's 3-2 win over Borussia Dortmund.
Son's adviser, Thies Bliemeister, revealed: "It is clear that other clubs are aware when a player scores two goals against the champions."