"It is vital that we get good quality games to prepare the squad for a tough season ahead," Merrick said.
"The games against West Ham and Newcastle United were fantastic but we need to keep progressing and getting everyone involved and this game is important.
"We had a similar game last pre-season in Rotorua and took many things from it.
"In fact, it played a part in young Matt Ridenton joining us and he went on to have a good debut season with the Phoenix."
The Phoenix will get their A-League campaign under way on October 12 against Perth Glory.
New Zealand A coach Neil Emblen said the encounter on Sunday would serve several purposes.
"We get an opportunity to see a number of our domestically based players in action ahead of the All Whites game against Uzbekistan in September."
The game is the second major football match at Owen Delany Park in Taupo in recent months after the Football Ferns met Brazil there in June.
*Tickets can be bought at the gate on Sunday at Owen Delany Park. Adults $10, children under-17 $5, children under-5 free.