After spending the 2015–16 season back in his country with FC Eindhoven, in the Eerste Divisie, van der Gaag moved to the top flight and successively coached SBV Excelsior and NAC Breda.
Following a stint with FC Eindhoven in the Eerste Divisie during the 2015-16 season, van der Gaag ascended to the top tier of Dutch football and subsequently managed SBV Excelsior and NAC Breda.