He said it was always a challenge playing at a higher level but he had been learning a lot with the Blues lately.
Nock first represented his country when he got selected for the New Zealand Schools side.
Taniwha head coach Richie Harris said the exposure Sam would receive playing for his country would put him in good stead come the Mitre 10 Cup.
He said it was encouraging that Northland was represented for the second year after lock Josh Goodhue got selected for the national grade side last year.
"The more players we have in that environment the better but that's the challenge we have," Harris said.
He said even if Nock did not get selected in the starting 15 or in the match 22, he would benefit from the national training programmes.
NZ Under-20 head coach Scott Robertson said the trial matches held last month were incredibly valuable for selectors who got to see players in an intense game environment, and how they responded to the pressure of playing and competing for places.
"While there are only the two countries, we have two tough test matches against a strong Australian team in this Oceania tournament. These will also provide us with a valuable sense of how they cope with playing intense matches in a compact window," he said.
Hurricanes' hooker Leni Apisai will captain the side.
The New Zealand Under-20 squad to compete in the World Rugby Under-20 Championship will be named in May after the Oceania squad returns home.
The squad assembles in Auckland on April 24 and will play against the Blues Development XV on April 28, before travelling to the Gold Coast for matches against Australia on May 3 and 7.