Eredivisie clubs are unhappy with the amount of Chelsea players on-loan at Vitesse Arnhem.
Chelsea have sent Patrick van Aanholt, Gael Kakuta, Lucas Piazon, Cristian Cuevas, Sam Hutchinson and new signing Christian Atsu on loan to Vitesse.
NEC Nijmegen technical director Carlos Aalbers said: "I want to be clear that I am not judging Vitesse or Chelsea because they are acting within the rules.
"But this is a new situation for us in Dutch football and it is worthy of discussion. It is six players on loan from Chelsea at Vitesse, but if this trend continues it could be nine or 10."
