Manchester United, Manchester City and Tottenham are all keen on the Spain international ahead of the summer market.
Schroder said of the 25 year-old attacker to Kicker: "I can only say that he feels incredibly comfortable with us.
"He hasn't just been here for six months and is just passing through, he has been playing for us for four years now."
Schroder added: "On the other hand, it is clear that difference-makers like Dani are of course in demand everywhere."