When Duhan van der Merwe was lining up for Edinburgh against Finn Russell's Glasgow, it's fair to the say the pair were not the best of friends.

"Playing against Finn and Hoggy [Scotland captain Stuart Hogg] I was always told you have to try and get in their heads," Van der Merwe laughs.

"That's why they probably didn't like me. We always got stuck into each other when Glasgow played Edinburgh, and now we're actually good mates. It's funny how it works out."

The restricted world of a Six Nations Covid 'bubble' could be suffocating but for Van der Merwe - a relative newbie to international rugby having made his debut in the autumn - it has been an opportunity to settle into the camp.

"The boys play a lot of Warzone [on the PlayStation]," the 25-year-old says. "We've got a dart board, we've got a pool table, and I probably drink about five coffees a day just to chat to the boys. You try and keep yourself busy, it's tough but you just have to get used to it.

"I'd like to say I'm up there with the pool, but I got absolutely smashed by our defence coach Steve Tandy. He's up 7-1, so credit to him. Darts, I'd probably say it's between Hamish Watson, Dave Cherry and Cornell Du Preez - obviously it has to be a forward.

"Coming in I was quite stressed, but the boys have made it very easy for me. We've got a very tight bunch here, I love being in the environment."

You could certainly say that head coach Gregor Townsend - and no doubt his team-mates too - have enjoyed having Van der Merwe in the squad, with the South African native once again in the starting XV to face Italy on Saturday.

His immense bulk and pace give Scotland a hefty ball-carrying option in the backs that they have often missed over the years, and his four tries in eight Tests - including the decisive one against England at Twickenham where he carried four white shirts over the line with him - suggest he won't struggle to bring his Edinburgh form of recent years onto the international stage.

That evidence has led to talk of a potential call up for the Lions series against South Africa this summer, a shout only strengthened by coach Warren Gatland's love of ball-carrying backs. For Van der Merwe, who grew up in George on the Republic's south coast and one day dreamed of pulling on the famous Springbok green and gold, it would be a strange twist of fate.

"For now I'm just focused on performing for Scotland and doing my best for the team," he said. "But if I get the opportunity to play for the Lions I would absolutely love it to go up against South Africa.

"It probably would be a wee bit strange. But I've been here now for four seasons, I feel like my rugby career is in Scotland. It's a tough one to answer, it would be strange but if given the opportunity it's something I would really look forward to."

Strange it may be, but nothing about Van der Merwe's rugby journey has been conventional. Bad injuries as a promising youth stifled his career at the Bulls, and then Montpellier in France. Edinburgh took a chance on him, and their investment has been rewarded by having the Pro14's most dynamic back on their books for the past four seasons.

That fruitful arrangement will come to an end this season, with Van der Merwe off to Worcester Warriors in the English Premiership. The move attracted some fierce criticism of the regularly under-fire 'project player' scheme, where Scottish Rugby bring players from the Southern hemisphere to Glasgow and Edinburgh with a view to them eventually representing Scotland under the contentious three-year residency rule.

"It probably doesn't look great," Van der Merwe acknowledges. "I've come over, qualified and leave. But I signed an extension three years ago, and then another extension so I've signed for four years and I can still play for Scotland.

"I just I want to test myself even more and potentially become a better player as well. So that's why I decided on the move.

"That's always something you have to think about as well [looking after yourself and your family], it's been tough times with Covid and pay cuts but at the end of the day, even if you take the money part away, I want to go and test myself in the Premiership."

While his rise has been meteoric, it has not all be plain sailing for Van der Merwe since his move to Scotland. Like many others he has been unable to see his family in the last 12 months due to Covid, and couldn't fly home to South Africa to support them when his grandfather died in June.

"He was a rugby player as well and just someone always looked up to," he says. "I still remember him dropping me off at the airport two years ago saying that whenever I play for Scotland he's definitely going to be there. But unfortunately he passed away.

"I miss home, I'm not going to lie about that, it's been tough.

"My family are very proud of me. I've gone through a lot of injuries and stuff and they're just happy for me that I stayed positive and kept on working hard. A lot of credit goes to my brother [Sale Sharks hooker Akker van der Merwe] as well, and he was very happy for me when I made my debut for Scotland.

"I'm a happy man and I've been enjoying it a lot."

And so to Italy, as Scotland attempt to salvage a Six Nations campaign which promised so much but the success of which hinges on seeing off the Italians in style, before trying to finish with a flourish in Paris.

The narrow losses to Wales and Ireland were "tough to take", says van der Merwe, who expects Italy to come to Murrayfield smelling blood.

"We were in the games for the most part but just couldn't get the last points on the board to get the win," he says. "Against Ireland, we probably only started playing 30-35 minutes from the end of the game, so we made it really tough for ourselves.

"We obviously spoke about that [bouncing back] to get the win again at BT Murrayfield, our home ground. Italy always target Scotland to get a win. They'll be up for it and we're looking forward to the challenge."