The agent of Real Madrid midfielder Rafael van der Vaart has challenged Manchester United to make a concrete offer for the Dutchman.
Van der Vaart has declared in recent days he would only leave Real for either United or Bayern Munich. Real are keen to sell Van der Vaart following the arrival of Mesut Ozil last week.
The midfielder's agent, Robert Geerling, declared: "Many teams want to sign him. But they must be able to convince Rafael to leave Real Madrid."
