PSV Eindhoven have lost John de Jong for the start of the Eredivisie season.
The attacking midfielder has undergone an exploratory operation on his knee after suffering some slight ligament damage.
Although the injury is not serious, he is only expected to be sidelined for one week - but that still rules him out of the match against Heracles.
The PSV medical staff now hope that De Jong's long-standing knee problems may be resolved.
Better news on the injury front for PSV was that DaMarcus Beasley and Mika Vayrynen have been cleared for the Heracles game.