Sir Ian McGeechan ranks the three best youngsters in world rugby

McGeechan said: "Another one off the Leinster independent schools production line (Blackrock College) and one of the standout No 8s in last season's Champions Cup. He would have been a Lion if not for injury setbacks."

"It is one thing coming through so young, but another to do it at Leinster, where the competition is so fierce. His ball-carrying, physicality and handling mark him out as a special talent.

"I would expect him to go on to win many Ireland caps."

McGeechan said: "You cannot put a price on outright pace. Rees-Zammit has it in abundance, and, combined with his finishing ability, you begin to understand why the hype surrounding him has been so intense.

"Warren Gatland's going to be spoiled for choice in the back three this summer."

DID YOU KNOW? Having started his youth career with the Cardiff Blues, he was released for being 'too small'

McGeechan said: "A bit of a throwback to my era in terms of his size (just 12.5 stone). But what a huge talent.

"Smith’s progression from Brighton College 1st XV to the Harlequins 1st XV was rapid and well-timed, with Nick Evans stepping back to coach.

"I have watched a lot of him. He never looks flustered on the ball, which is the hallmark of a great player.”

DID YOU KNOW? Born in the Philippines to a British father and a Filipina mother, Smith picked up the game of rugby union at the age of seven with Centaurs RFC when his family moved to Singapore