The 19-year-old playmaker has recently been linked with the likes of Arsenal, Manchester United and Real Madrid.
Dortmund’s general manager, Michael Zorc, told Bild: “We have agreed with Mario that he will be playing for Borussia Dortmund during the new season.
“He is under contract with our club until June 2014. He has no reason to move on. We have no need to sell him.”
