Klaas-Jan Huntelaar has again failed to rule out leaving Schalke this summer.

Huntelaar is being tracked by Manchester United, Tottenham and Liverpool, among several European heavyweights.

"I cannot express as a percentage of how likely it is that I stay here," he told BILD.

"I'm now 28, which is the time when a footballer is at the top of his game. And of course, the time of when you should be getting your best contract - though winning titles is also important."