Bobson has failed to stamp his class on the Spanish league during his time with Espanyol and has opted to return to Holland, while Kreek has quit AEK Athens in favour of a crack at life in De Eredivisie.
Kreek has signed a two-year deal, while winger Bobson has pledged the next four years of his career to the Tilburgers.
Bobson is keen to get his career back on track in Holland.
"Espanyol didn't turn out to be what I expected," Bobson told De Telegraaf. "I'm keen to show what I am capable of at Willem II."
