Robertson recently went to Japan on a scouting mission, looking at how his potential charges are performing ahead of the July series.

The 49-year-old watched on as a Brave Lupus Tokyo side featuring Shannon Frizell and Richie Mo'unga defeated Sagamihara Dynaboars 41-19.

Robertson also took in Ardie Savea's Kobe Steelers as they succumbed 28-18 to Japan Rugby League One leaders Saitama Wild Knights.

Savea is set to return to New Zealand ahead of the mid-year Tests, alongside Tokyo Sungoliath's Sam Cane and Toyota Verblitz's Beauden Barrett, but Mo'unga is currently ineligible after signing a long-term deal in Asia.

Meanwhile, Frizell's future is unknown, but it is unlikely that the back-rower will be available for the All Blacks in July.

Their new boss, who took charge following Ian Foster's departure, was therefore asked about the eligibility laws, given that he urged New Zealand Rugby to "keep an open mind" over them.

"Our current eligibility rules stand and there's been no change," was Robertson's response.

"He (Mo'unga) is playing good rugby, isn't he? Exceptional, he's probably the form player (in League One)."

It wasn't just the performance aspect that Robertson was looking at but also their physical state ahead of the return of Barrett, Cane and Savea.

"Our players are in great physical condition, we're really pleased," he said.

"We think that they're well looked after, they're well coached (and) they're in a situation where they come back to New Zealand in good condition."

Plenty of Kiwi players and coaches have moved to Japan, but the league is also benefiting from their strength and conditioning expertise.

"There are a lot of familiar faces who have come through the system in New Zealand, so it's good to see them having a good time in Japan," Robertson added.

"I think the quality on and off the field is definitely building.

"We know the quality of Japan rugby. On the day a lot can happen, so you have to be ready for that match ” the speed, the quality of skills, the variation and the innovation of the match, and the passion of the crowd."

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