The side has for the first time in the tournament's history failed to qualify for the top eight and is now focused on winning the bottom eight.
Otago is in the South Island regional pool of four teams with the top two going into the top eight at the tournament.
Otago lost heavily to Tasman and then bounced back to beat Southland.
In a crunch game against Canterbury in Christchurch last Saturday, Otago lost 27-21.
It was leading 21-20 going into the final minutes but Canterbury scored a try in the corner to win the game.
Otago coach Luke Herden said it was a close contest and Otago had played well right throughout the match.
The national under-19 tournament started in 2014 and Otago has made it into the top-eight semifinals twice.
Herden said the side was taking it one game at a time and first up was Counties-Manukau which had qualified as the fourth-best team from the Chiefs region.
Otago had improved in its three games and would be looking to continue this upward trend, Herden said.
The side is captained by Slade McDowall and also includes other premier players such as Woody Kirkwood and Ricky Jackson.
Herden said Tasman had become a formidable team over the past year as it had been a part of the wider Crusaders academy. The Crusaders had an active academy in which players could be loaned out to both Canterbury and Tasman, boosting the game in the top of the South Island.
The tournament in Taupo numbers 16 teams. The other games will be on September 13 and September 16.
