The aches of his trade, the lingering effects of illness are dismissed instantly. His eyes light up.
'My first rugby ball? That is a story.' The face breaks into the sort of smile that illuminates a Glasgow
'I was blessed that my dad bought me a ball. It was so expensive. It was very unusual to have one. A privilege,' says Nikola Matawalu, otherwise known as Niko - and as the sort of rugby player who seems to have the unerring aptitude to inject spectators with a jolt of adrenaline.
'In Fiji, you play rugby as soon as you can walk but a ball was very rare when I was young,' he says of his homeland where rugby is a mandatory lifestyle rather than merely a sport.
'But I will tell you the story of the ball. My father had been a military officer but he was a padre then. I would miss church every Sunday to go and play rugby. My father would smack me, give me rows.
'But then he said to me one day: "Here is a rugby ball. You will come to church on Sunday. But you can play with the ball on Mondays."'
Sunday became a day of rest and religion. Rugby was the article of faith for the rest of the week. 'You have to know that rugby is just the culture in Fiji,' says Matawalu who, at 29, has dedicated his professional life to the sport.
'Once you start to walk, then that is when you start playing. Simple. It is something that is there. Just there. You just do it. No one teaches you.
'Sometimes we used a bottle as a ball. We would put just a little bit of water in it to give it some weight. We also used a ball of paper tied up with plastic strips. And yes, it's true, we would play with a dry coconut. It was anything that we could throw.
'Everyone wanted to play. These are my early memories of life - playing Fiji touch. All the pro clubs play it now. We just called it touch. If you were touched when you had the ball, you lost possession. You went to the beach or down by the river to play. It was a simple schedule. It was play rugby whenever you had the chance.
'I loved to play with the big guys. My older brother was 11 years older than me but I played with him and my other brother, my cousin, my friends. It was every afternoon.'
Matawalu is now a Glasgow Warrior. He breezes into a room in Scotstoun after a team meeting, genuinely pleased at being voted the McCrea Financial Services Player of the Month and relieved that an illness that prevented him training has passed, although it has ruled him out of tomorrow's crucial European Champions Cup match against Cardiff Blues.
Robbed of an intense focus on a big match, Matawalu can instead reflect on a life that is infused by rugby but has other significant ingredients, most notably his past as a member of the Fijian Navy, his duties as a human being and his responsibilities as father.
His rise in rugby was swift. At 11, he was playing for the country's under-13s team and he progressed through the ranks to the national side. After an education at Suva Academy, he joined the navy patrolling the waters around Fiji and playing for the service. It did have an effect on his career.
'First, I trained hard in the three years I was in the navy,' he says. 'But, second, I was not allowed to go to play in Australia because of the diplomatic row after the coup in Fiji in 2006. As a military person, I could not go there.'
His life changed in 2012. 'Scotland came over to play and I was blessed to be named man of the match,' he says.
'After the match I went through my recovery routine and I was in the pool when someone came in and handed me a phone. Gregor (Townsend, then coach at Warriors and assistant coach at Scotland) was on the line. He told me: "We are going to do everything to bring you here."'
Matawalu soon landed in Glasgow.
'All the people were saying it was crazy cold but I was not bothered,' he says. 'I looked at this way. It was a door that opened and opportunity only comes once. I love experiencing different cultures and that is why I grew as a rugby player and a person.'
The interview then becomes a tale of three Nikos. The first is his father, the padre.
'You have to try to understand everyone. You have to open up, talk to different people, says Niko the second, the rugby player.
'My dad told me this before he passed away seven years ago: if you go somewhere new, you have to enjoy the place, then you need to love the food and, thirdly, you need to enjoy everything, every day.
'You cannot be homesick if you do this. I came over with no one, no family. But the people here are fantastic and I love them.'
He wanders around Scotstoun and his home in the West End calling everyone 'babies'.
He chuckles: 'It relaxes everyone. You do not know how someone's day is going, how they are. You need to be open and friendly. My personality is that I don't pretend who I am. I am just me.'
Matawalu has been embraced by Scots with a roar of anticipation echoing around Scotstoun when he touches the ball.
'It is a special thing what I have in Scotland. This is like my second home. I would consider staying on here after I retire, though my wife wants to go back to Fiji,' he says.
So why is Glasgow special for a player who has performed all over the world and in club rugby at Bath and Exeter Chiefs?
'It's the people. The city is so beautiful, too, but it is the people. It was my first period away from home and they made welcome. That was so important.'
The maverick Matawalu, though, was initially an education for rugby players attuned to specific gameplans but he insists now that he has refined his game to accommodate the realities of the modern game.
'No, there are no difficulties in following tactics,' says the player who now operates mostly on the wing rather than at scrum half.
'The gameplan is there but, in sport, you have to play what is in front of you. If you see the gap, you use it. You can't be dumb about this. You have to play in the moment.'
This philosophy informs how he looks at his career.
'I plan day by day. I achieve more if I focus and set goals day by day. I have tried the other way of looking for a long-term career plan but it is better in the day. It's simpler. You never know in rugby,' he says.
'But family life is different. You have responsibilities, so you must have a plan.'
He believes in God and still attends church.
'I went at New Year and some Sundays there is a church near to me and I sometimes walk there. It is something that is put in you when you are young. It has stayed with me.'
The other religion of rugby has remained with him, too.
'Yes, I still love it and I want to pass it on to my children.'
This sentence heralds the appearance in conversation of the third Niko, his son of 26 months.
'I have another boy, Cassius, who is six months but obviously he is too young to play with a ball,' he says.
But Niko, the third, has already impressed his father.
'He is good,' he says with a laugh. 'But he mostly plays football. I gave him the rugby ball at first and he screwed up his face. But now he plays with both. I wish my father was here to see this.'
Niko, the first, survives, though, in the legacy of the rugby ball. It is the pass that has spanned more than two decades and run along three generations. There is energy in it yet.