James Ryan's rare mix of humility and talent marks him out as a future Ireland great, according to Simon Easterby.
Fast-rising lock Ryan faces the biggest game of his embryonic Test career on Saturday when Ireland take on Samoa bidding to secure a World Cup quarter-final spot.
The 23-year-old has Leinster team-mate Dan Leavy to thank for the tongue-in-cheek nickname of 'Big Cheese', but forwards coach Easterby explains that in reality Ryan is as far away as possible from any 'Big I Am' persona.
Ryan is already being touted as a future Ireland captain, but Easterby backed the 21-cap second row to carve out a Test career of true renown whether he leads his country or not.
"He comes across as being quite quiet but actually he's a real student of the game," Easterby said.
"He works incredibly hard on the physical element, but certainly the mental part of the game too. There's no 'Big I Am' about him, even though his nickname would suggest otherwise.
"He's just a guy who will continue to grow and will continue to lead, whether that's through having a 'C' next to his name or just through his actions.
"He will become one of the greats, I've no doubts about that."
Ryan made his Test debut even before his senior bow with Leinster, such was Ireland's faith in their fast-maturing lock.
The sharp-witted youngster came off the bench in Ireland's 55-19 win over the United States in Harrison on June 10, 2017, and has stormed from strength to strength ever since.
"He's come through the ranks, hasn't he? We plucked him, I don't think he'd even played a senior game for Leinster when we took him to the States to make his debut," Easterby said.
"Maybe there were a few eyebrows raised at that. But he hasn't disappointed.
"He's a phenomenal athlete. He's certainly on the right track currently. He works incredibly hard.
"And that I guess is the baseline for any great player: that they have the raw talent and the ability but that they also work incredibly hard. And he has all three."