Bayern Munich's director of sport Matthias Sammer has warned off any clubs from making a move for Mario Mandzukic.
The Croatian target-man has 24 goals to his name this season and has been a key performer under Pep Guardiola.
However, the impending summer arrival of Borussia Dortmund's Robert Lewandowski has led to intense speculation that Mandzukic will then be sold.
But Bayern remain insistent that Mandzukic is staying put, and talks over an extension to his contract, which runs until 2016, have begun.
And, speaking to Sky Deutschland, Sammer warned: "No one needs to start knocking on our door about Mandzukic.
"He is incredibly important to Bayern.
"I always affectionately say that he plays like an animal. It is simply amazing how much work he does for the team and how much running he does during a game.
"They always try to provoke him because he really hurts his opponents with his work-rate."