"He's a pretty impressive person and he's been a very impressive fullback. He's certainly jumped up the ladder on the best fullbacks in our game. In terms of his potential ... it's limitless."
Robinson also revealed that he was a major influence behind Tuivasa-Sheck's controversial decision to make himself unavailable for the 2014 Four Nations, citing fatigue after two years of almost non-stop football. At the time, it was an unpopular decision among Kiwis fans but now might be regarded differently.
"It was mostly my call," said Robinson. "I thought for the future of him — and also New Zealand rugby league — he needed to learn that position. It takes a long time to learn fullback. It had been a long season and he hadn't had an off-season due to the [2013] World Cup. I talked to [Kiwis coach] Stephen Kearney and that is what resulted."
From November last year, he learnt his new trade, putting in the hours to master one of the most important positions on the field.
"He stayed back, didn't play [the Four Nations] and we worked hard on his fitness, positional play and work around that position. As a fullback, he flew out of the blocks this year."
In his first NRL game at the back, Tuivasa-Sheck carried for 195m and contributed eight tackle busts, two line breaks and a try assist. That was just the beginning.
He has since exceeded 250 running metres on three occasions, and topped 190m in nine other games. He is averaging 207m per game — more than anyone in the NRL — and he also broke the 300m barrier in round five, which has been done by only 11 other players since 2002.
"Roger is the next breed of superstar in our game," says Robinson. "He's got a strong mindset, he knows what he wants and he is pushing the limits, creating some new stuff for fullbacks to do. "
In recent weeks, Tuivasa-Sheck has exhibited more of a passing game. Rather than just looking for the gaps as he chimes into the line, he is looking to create gaps.
"He's adding more to his game," says former Roosters and Kiwis fullback Richie Barnett. "Roger wants to be the best in the No1 jersey. There's probably no one better in terms of a running game at the moment but as his distribution improves, he could be anything."
Robinson is philosophical about Tuivasa-Sheck's impending move back across the Tasman, which surprised most observers when announced in April.
"I've said before, we are the Roosters and we will produce some players," said Robinson. "He's not irreplaceable. He's a great man and he is a loss to us but we'll be fine."
