Matavz will move to Italy at the end of the season.
"On the last day of the transfer window negotiations with Napoli faltered due to a loan issue, but we have already reached an agreement to complete the transfer in July," agent Musret Jashari told Radio CRC.
"Matavz is a great lad who has matured and done well in Holland. He has great power in his legs and will make a great partner for Edinson Cavani in the Champions League.
"Coming to Napoli will be a great opportunity for Tim."