''The squad for (the World Cup) is named on January 8 so we want to ensure every player in contention is given a chance on the international stage," Edgar said.
''We need to know we've left no questions unanswered."
Ryder, 30, has been included to evaluate his progress in an international touring environment, Edgar added.
He stressed Ryder has been chosen only for NZ A - ''nothing more, nothing less".
"It's an important step for Jesse but it is only a first step and we're anxious not to get ahead of ourselves.
"Like everyone else in the squad, his future prospects will depend on his performance, on and off the field in Dubai."
Auckland veteran seamer Kyle Mills will captain the A side, which also includes returning left arm spinner Dan Vettori, and three other seamers, Matt Henry, Mitchell McClenaghan and Adam Milne.
The NZ A squad: Kyle Mills (captain), Martin Guptill, Anton Devcich, Jesse Ryder, Dean Brownlie, Colin Munro, Colin de Grandhomme, Nathan McCullum, Derek de Boorder, Dan Vettori, Adam Milne, Mitchell McClenaghan, Matt Henry.