The Green and White Army maintained their winning start in Group F last night courtesy of a comfortable 2-0 win over the European minnows at Windsor Park.
"The results in the group have been good for Northern Ireland and maybe they can qualify," Olsen told Press Association Sport. "In Hungary they were very good and at home they play very well.
"Greece is still the strongest team in this group, despite a slow start, but to have six points already is good for Northern Ireland - you cannot take that start away from them."
Next up for Northern Ireland is a trip to Greece on Tuesday night.