"I think if they leave it to Thursday [the tickets] be gone," he said.
Mr Morrison said preparations for the annual event were going well and the stage is expected to be erected tomorrow morning.
He said the performers were looking forward to getting on stage and it wound be the first time for some performing in front of a Rotorua audience.
The cast for this weekend's concert includes Ria Hall, who opened the Rugby World Cup last year, seasoned performer Tina Cross, actress and performer Jennifer Ward-Lealand, singer and television personality Russell Harrison and Kiwi rocker Michael Murphy.
Also performing are physical theatre performers Mike Edward and Eve Gordon, New Zealand's premier trombone quartet BonaNZa, singer-songwriter Sharon Emirali, pop singer Seth Haapu, vocalists Ellen Kuiper and Elisha Fai-Hulton and musician Cameron Clayton.
With Rotorua's fine weather expecting to continue, Mr Morrison said the event would attract record crowds.
According to Metservice, Rotorua will be fine until next Wednesday.
On Saturday temperatures will reach 22C and will be dry with little wind.
Mr Morrison said with the huge crowds that are expected to attend, he's encouraging members of the public to be safe and look out for one another.
"We're a family event and it's important that people look after each other."