Feyenoord chief Martin van Geel knows defender Stefan de Vrij is considering his options.
Inside the final two years of his current deal, De Vrij has stalled at opening contract talks with Feyenoord.
"I understand that Stefan de Vrij is wondering how Feyenoord next season will look," said Van Geel.
Voetbal International says Chelsea have made a €6million offer for the stopper.