It will provide about 9500 seats, boosting ground capacity to about 22,750, of which more than 2000 seats are still to be sold.
They include seats in the Harris Stand, which have just become available and will go on sale on Monday, says Hawke's Bay Rugby Union marketing manager Jay Campbell.
"People have been saying it's sold out, but it isn't yet," he said, confident the Napier climate and the Hawke's Bay sporting fanaticism would attract the biggest crowd to the park since the halcyon days of Hawke's Bay's 1966-69 Ranfurly Shield era.
"We need to show the rest of New Zealand how passionate we are about the footy in Hawke's Bay," he said.
The public will get an impression of how it will look on Saturday when the Hawke's Bay Magpies ITM squad plays a pre-season game against Waikato, and traditional local big-match rivals Taradale and Havelock North face off in the final of the Maddison Trophy premier grade clubs final.
A Magpies training run yesterday, in which newcomers played for their locker positions in the changing room, also brought some reality to the moment as the mayor watched from his seat in in the sun with union CEO Mike Bishop.
Freed from the exercise for a few minutes, star player Richard Buckman said he would be at the test, despite the commitments to the ITM Cup, and the fact he hasn't, yet, realised a dream of playing for New Zealand.
Just 24 hours earlier, the Magpies will have played Northland in Whangarei and Buckman says he hopes there are no flight delays so the team makes it back to Napier in time.
"Hopefully we'll have a packed-out house, and the game will give us a chance to catch up with a few of the boys," said Buckman, 25.
After a good Super 15 season for the Highlanders, he still hopes to make his way up and eventually be in the All Blacks.
"I guess it's everyone's dream to get there. But I'm going to have a good season with Hawke's Bay and then head back down to the Highlanders down south."
While he has sunk his toes into a bit of rugby league in the past, he says rugby union is definitely his future.
Mr Campbell last night also revealed a limited number of "sight-restricted" seats at a reduced price.