Van Ass started playing hockey at Victoria, a field hockey club in
Rotterdam. In 2008 he switched to
HGC, with whom he won the
2010–11 Euro Hockey League. In 2013 he returned to Rotterdam to play for
HC Rotterdam, where he played for five seasons until 2018 when he returned to HGC. In his last season before his retirement HGC was relegated from the
Hoofdklasse. ==References==