Dekker had limited opportunities at AZ after the arrival of Wesley Hoedt, making 56 appearances in the first team and four in Europe. VoetbalPrimeur report that he will now look to make more appearances in the Eredivisie with Willem II. The defender himself stated that he sees this move as a new chapter in his career, having completed his youth development at AZ and playing in the first team.

Technisch directeur Freek Heerkens praised Dekker's abilities, saying that he is a young, strong defender with experience gained on various levels. Heerkens added that Dekker will bring competition to Willem II's defence.