Ireland coach Joe Schmidt was quick to dispel comparisons between Ireland's James Ryan and Maro Itoje, England's 2017 World Player of the Year nominee.
"I am not sure they would have the same athletic profile," he said.
"I think the fact Maro Itoje plays number 6 a lot, James is a pure second-row."
While the St Michael's College graduate is a rookie, there are undeniable physical and mental attributes that make him a thoroughbred prospect.
"I think James is a little bit taller than Maro Itoje, so that line-out extension is something that is important to us."
The difference in age - there is just two years in it - is dwarfed by the big-game experience Itoje has gained from Saracens, England and the British & Irish Lions.
In addition, Ryan has been held back by last season's serious Grade-3 hamstring tear and a number of niggling inconveniences that have prevented him from putting a series of games together for Leinster, never mind in the unforgiving international arena.
Schmidt is understandably determined to protect the 21-year-old.
"I think James is just a kid really," he said.
"He will fill out and I think he is going to be a big engine room contributor to us in the future, at least that is what we are hoping will be the case.
"You know it is hard to predict someone's future but with the work ethic, intelligence, physique and commitment that he does have, it is a very good starting platform that he has."
In his previous incarnation as Leinster coach, Schmidt caught a glimpse of Ryan, aged 15, and filed it away.
He was more inclined to align Ryan with Tadhg Furlong for the trajectory of his career, in having the physical stature to play two years at each international age grade.
For now, the 21-year-old has to grow by learning on the job as one half of an unbelievably exciting second row partnership with Iain Henderson.
"I don't think you can ever really accelerate it," cautioned Schmidt.
"All you can do is try to best prepare them for what is coming up.
"His size is what it is, you can't really accelerate that without I suppose putting too much stress on him.
"But I think when you get put in pressure situations what you learn from that allows you, potentially, accelerate your understanding of the game, your understanding of pressure moments in the game and where your decision-making is crucial.
"The quicker you can make those decisions, the more instinctive those decisions are based on that previous experience.
"That's the difference between having someone new and naive and someone who's 'I've been here before' or 'I know what I am doing' and they get it done."