Three minutes into the second half at Scotstoun on Friday night, Bath's Piers Francis had the misfortune to go high in a tackle on Glasgow Warriors' runaway buffalo Sione Tuipulotu. The outcome was not pretty.

The grandson of a Scot and an Italian, the son of an Australian and a Tongan, a native of Melbourne before spending time playing in Japan, the 25-year-old has got a lot of influences to draw on and a hell of a story to tell.

But there is an elephant in the room when he sits down to talk and we may as well address it. It goes back to the penultimate game of last season's Six Nations, his first championship as a Scotland player.

After returning from their win in Rome, six Scotland players left base camp and went on an unauthorised trip to a city-centre boozer when they were supposed to be in the bubble of their hotel. Tuipulotu was one of them. Having featured in all four of Scotland's games to that point, he didn't make the squad for the final one in Dublin.

There's no mealy-mouthed explanation here, just total ownership of an error.

"I've never spoken about it publicly, but ultimately I felt a bit embarrassed," he said. "We were probably naive to the fact that we were doing something wrong, but then you realise how wrong it is.

"The biggest part I regretted was letting down my team-mates. I just felt that I got a little bit ahead of myself. We were just having a bit of fun, but there's a time and a place for that stuff and it wasn't the right time or place."

Tuipulotu said he was determined to learn a lesson from that experience and, clearly, he has. In a crowded field, he is Scotland's form centre, a guy who has brought his game to a new level this season. He has been hugely influential in Glasgow's resurgence, a bludgeon and a rapier. His influence grows all the while.

He laughs when recalling his move to Glasgow in the summer of 2021. Some of his mates in Shizuoka, where he was playing at the time, wondered why anybody in their right mind would swap the south coast of Japan for what they called "the grimmest city in the UK".

Replace "grim" with "great". After a tricky settling-in period - "my first winter, the darkness got me the most, I was freaking out a bit" - he is now a champion of the city. He could bang on all day about the beautiful leafiness of the West End.

It's his journey that's the thing, though. And it starts with his grandmother, the proud Scot, Jaqueline Anne Thomson, a lady whose accent has never left her despite living most of her life in Melbourne.

"She helped raise me and my brothers and sisters," he explained. "I get emotional when I talk about my granny, because when my mum and dad were out working really hard, my grandma looked after us. Not everyone has the privilege of growing up with their grandparents and I really grew up with my grandma. She's so close to my heart."

The connection, you can tell, runs deep. Tuipulotu has never pretended to be anything he's not, has never said he's a Scot when the truth is obvious. But it's worth listening to him on this because we can be cynical about this stuff.

"I came here as a foreigner and I am a foreigner," he said. "I'm from Australia and I don't expect anybody to think I'm some Braveheart Scottish guy. One thing I say to my grandma is that, when I pull on the Scottish jersey, I feel it, you know? People on the outside looking in go 'these guys are foreigners, they don't take pride in the jersey', but when I'm representing my grandmother, there is pride in the jersey.

"It's not something I take lightly at all. I take it very seriously. We have family gatherings in Melbourne and we have our Tongan family, we have our Italian family and our Australian family and then my grandma, who's the matriarch. She messages me Scottish phrases on Facebook. She says 'out and about' and puts quadruple o's in it. Sometimes I have to ask Duncy [Weir] what it means. Duncy's my translator."

Jaqueline married an Italian and their daughter married a Tongan, Tuhefohe, who made it to Scotland last year to see his son come off the bench in the Calcutta Cup win.

Tuhefohe is one of his great heroes, a man who worked in security and warehousing before working his way up and taking over the company for which he previously laboured.

"We grew up in an area called Frankston," Tuipulotu said. "The reputation isn't great, but I had everything growing up. My parents lived a very hard life and I lived a really privileged life."

'Time for Scotland to turn up and deliver'

Tuipulotu says that it took a while for the penny to drop about how fortunate he was. In his early years, he was a troubled soul, an angry young man.

"I got a part-scholarship to go to St Kevin's College [his family still had to work hard to afford the fees] and that's when my life changed," he said. "I was 14 and ignorant towards a lot of things. I looked at the kids there and I thought they're not like me. I felt out of place other than when I was playing rugby.

"Even before I went to St Kevin's I was an angry kid, angry at what was happening around me, frustrated because I didn't know what I was going to do with my life. My mentor, Mr Windle, an English guy from Newcastle, was my tutor, and changed my whole outlook.

"He saved me getting expelled a couple of time and got through to me. I owe a lot to him. I stopped having a chip on my shoulder and started to embrace the fact that I was at one of the best schools in Melbourne, a place that my parents worked hard to get me to."

His Scotland debut came against Tonga, the country of his father's birth. The greatest day of his rugby life came against England last year though. Nothing could have prepared him for that.

He says he'll remember for the rest of his days getting off the bus at Murrayfield and looking at the Scottish youngsters serenading the team in the door. "That's probably when I'm at my most motivated, when I'm looking at the little kids and their families," he said. "You don't want to let them down."

The championship is almost upon us again and once more it's England up first. As ever, there's hope in Scotland laced with bitter reality. He thinks fans must be sick of hearing from players that this could be their year, saying: "It's time for us to just do it, to turn up and deliver."

In Australia, his greatest fan sits and waits for the championship to begin. In geography terms, she's a world away from her increasingly famous grandson. Emotionally, she'll be with him every step of the way.