August 17, 2006, the Boet Erasmus Stadium, Port Elizabeth.

South Africa, showing none of the assurance that would sweep them to World Cup glory the following year, are stumbling to an unconvincing 29-15 victory over Scotland, their scoreline flattered by a combination of good luck and helpful refereeing.

Having given up all pretence of trying to win the game in any style, Springboks full-back Percy Montgomery lines up yet another kick at goal. All around the ramshackle old ground, the local supporters are whistling their derision. With the exception of one. Dave Denton is too busy shouting for Scotland.

Denton was just 16 then, a pupil at nearby Kingswood College. He had gone along with a few friends – "they weren't happy with me wearing a Scotland jersey" – and it was his first taste of international rugby at close quarters. In terms of his life's narrative, it would be lovely to report that he set his heart on becoming a Test player there and then. Lovely, but wrong.

"It was all still a bit far away for me," Denton recalls. "I was a lot smaller back then and I had a lot of growing to do. At that age, it was really just a bit of fun to watch the game. It wasn't until my final year at school, when I started playing the provincial stuff, that I really thought that I could play professionally."

His recollections of the occasion are sketchy. He remembers Chris Paterson making a break and Schalk Burger picking up a serious neck injury. Like he says, he was just a kid enjoying a day out with his mates. Having a bit of fun.

Seven years on, rugby is a serious business for Denton. And not just because it is how he earns his living, but also because he has now reached what could be a crossroads in his career.

Denton made a sensational run-on Test debut last year, named Man of the Match for his vivid performance against England in his first start for the country of his birth. He backed that up with more impressive displays in the Six Nations, but then missed Scotland's Australasia tour that summer. The rest should have done him good, but he was anonymous in Edinburgh's early-season games and was demoted to the Scotland bench for the opening autumn Test, against New Zealand.

He returned against South Africa and Tonga, but was back among the replacements for this year's Six Nations, overtaken in the pecking order by a resurgent Johnnie Beattie. Denton had seemed a shoo-in for the Lions 15 months ago, but his name was hardly mentioned as selection loomed. As he returns to South Africa with the Scotland squad which is taking part in the four-team Castle Lager Incoming Series over the next few weeks, he knows he needs some big performances.

"This is a great tour for me to be able to re-establish myself and get back on the scene," he says. "I think the most important thing for me is to play my part in the team in whatever way I can.

"We want to build on our Six Nations performances. When we last toured [in 2012] we got three wins, which is at the forefront of my mind. I obviously want to be starting Test matches. I need to prove myself to earn that back.

"I've been out injured for 11 weeks now, so I've got a lot of making up to do. But I'm confident that I'm capable of doing that."

Denton's absence was the result of a knee problem he picked up playing for Edinburgh against Scarlets. It was an all too typical event in a season where, for one reason or another, he was never able to string together a sequence of decent games. He also concedes that, in his determination to avoid second-season syndrome, he actually tried too hard and ended up going down with a hefty dose.

"There was a stage at the start of the season where my form dipped," he admits. "There were issues with me putting too much pressure on myself. But, to be honest, I thought the autumn internationals went well, and I played well against South Africa and New Zealand in particular.

"The problem I've had this season is that every time I felt I was getting momentum and starting to play well I injured something. It's part of rugby and it's always going to happen, but I just hope it doesn't happen too many more times."

After his most recent period on the sidelines, Denton can hardly expect to be given a place in the starting XV for Scotland's series opener against Samoa in Durban on Saturday. With John Barclay already ruled out, a more likely deployment is as bench cover for a back-row of Beattie, Al Strokosch and Kelly Brown, although coach Scott Johnson may be tempted to allow the fast-improving Ryan Wilson more game time.

After completing school in South Africa – his family home is actually in Zimbabwe – Denton came to Scotland primarily to study economics at Edinburgh University. Over the next three years, he fast-tracked his way through Edinburgh Accies and the Edinburgh professional side to become a full international player. Does he return to the land of his upbringing with a sense of having proved himself? Does he go back in triumph?

Denton smiles and shakes his head. "There are no differences between the teams you play against," he says. "A Test match is a Test match and we look forward to all of them. But yes, I suppose there is something special about going back to Africa and playing there. With time off afterwards, I'm going to be there for about six weeks, and that will be great."