At the moment, Janssen has played 247 official duels in the FC Utrecht shirt. He scored 26 times in it. At 35 years, 2 months and 21 days, Janssen is the fifth oldest goalscorer on behalf of FC Utrecht. Only Leo van Veen, Alfons Groenendijk, Willem van Hanegem and Wlodzierz Smolarek were older. Now that Janssen has decided to stop, if he still scores this season, he can only overtake Van Veen.