Spanish club Real defeated Ajax twice in last season's Champions League but Kluivert is of the opinion that the Eredivisie outfit are better equipped this time around.
"Ajax can cause an upset against Real Madrid. They have some great players who can be decisive, although it will be a very difficult task," Kluivert was quoted as saying by Ona FM.
"It is important that Ajax play their own game and press high up the pitch. Things will be extremely difficult when they decide to sit back and defend deep. Dropping deep is suicide against Madrid."
Kluivert is currently coaching the FC Twente youth team.