Hurricanes hold onto Jordie
Barrett is currently with the Hurricanes and is enjoying a stellar season so far for the defending Super Rugby champions.
Meanwhile, Blues flyhalf Stephen Perofeta has been ruled out of the Oceania tournament due to his ongoing recovery from an ankle injury.
Former New Zealand Secondary Schools representatives Thomas Umaga-Jensen and Ciarahn Matoe has joined the squad.
New Zealand U20 head coach Craig Philpott said he was pleased with the depth of the squad.
"We have been following Thomas's return to rugby following his hip surgery in October last year with a view to inclusion in the squad," said Philpott.
"He's had three weeks of club rugby and is tracking well. We know what he is capable of after his time in the Secondary Schools team and he is a welcome addition now that he is injury-free.
"With Stephen and Jordie not available we needed extra cover at flyhalf. Ciarahn's time with the Chiefs U20 squad has gone well and he proved himself with the New Zealand Secondary Schools team last year. This is a good opportunity for him and one I am sure he will make the most of.
"We had hoped that Stephen would be available for selection. However, it's become clear he won't be ready in time for the tournament due to his ankle injury.
"As has been the case in previous years' players have been deemed unavailable for the Oceania tournament due to their Super Rugby commitments. No final decision on their availability for the World Championship in Georgia in May and June has been made."
The squad will travel to the Gold Coast for matches against Fiji on April 28, Samoa on May 2 and Australia on May 6. All matches will be played at Bond University, Gold Coast Rugby Fields.
New Zealand Under-20 squad:
Forwards: Harrison Allan, Asafo Aumua, Sam Caird, Adrian Choat, Tom Christie, Ryan Coxon, Tim Farrell, Alex Fidow, Luke Jacobson (captain), Ezekiel Lindenmuth, Marino Mikaele-Tuu, Dalton Papalii, Jacob Pierce, John Sauni, Samuel Slade, Pouri Rakete-Stones, Isaia Walker-Leawere,
Backs: Caleb Clarke, Ereatara Enari, Braydon Ennor, Tima Faingaanuku, Tiaan Falcon, Will Jordan, Kemara Hauiti-Parapara, Orbyn Leger, Ciarahn Matoe, Josh McKay, Jona Nareki, Carlos Price, Tamati Tua, Thomas Umaga-Jensen.