Just a few months ago it seemed Tom Heathcote's lasting contribution to Scottish rugby would be to redefine the term "one-cap wonder".

He had his one cap, and everyone wondered where he had gone.

To say Heathcote fell off the radar screen would be an understatement of considerable proportions. Hailed by Andy Robinson as the player who could solve Scotland's perennial fly-half problems, Heathcote came from nowhere and went straight back there after a 10-minute appearance at Pittodrie as a replacement against Tonga.

He popped up, and he popped back down again. A kind of rugby meerkat, you might say. Actually, the tale of Tom Heathcote says much about the parochialism that prevails in the Scottish game.

Long before Robinson championed the player's cause for Scotland, the Bath prodigy was fast-tracking his way up the English ladder, a rising star for our friends in the south. In fact, only a year ago he was in South Africa, playing for England Under-20s at the Junior World Cup.

It took considerable arm-twisting by Robinson to persuade his fellow Bath resident to turn his compass dial north, and take advantage of the accident of family circumstances. Heathcote's father, Gareth, was an RAF pilot stationed at Kinloss, meaning the now 21-year-old drew his first breath in Inverness.

Hence those 10 minutes against Tonga, a debut in little danger of being remembered as the most triumphant in Test history. Scotland slumped to a 21-15 loss, with Heathcote's most noteworthy contributions being one fluffed kick at goal and the knock-on that brought the game to an end. When Robinson resigned as head coach the following day, Heathcote looked to be in danger of going down with the ship. And as far as many Scotland supporters were concerned, that's exactly what happened.

But here he is in South Africa, seven months older, seven months wiser and, in the opinion of the interim coach Scott Johnson, rather more than seven months better as a player than he was on that calamitous November day in Aberdeen last year.

Johnson makes no bones about the fact the fly-half position, filled for more than 20 years by the holy Borders trinity of John Rutherford, Craig Chalmers and Gregor Townsend, has been a problem for Scotland in recent times. Dan Parks did a noble shift in adverse circumstances, but since the turn of the century no player has ever really nailed down the berth as his own.

Could Heathcote be the man? The former fly-half Johnson has delivered his vote of confidence by handing him the playmaking duties against Samoa, and the player has an air of mature assurance as he sits down to talk in the Scotland team hotel a few miles north of Durban.

Not cockiness or arrogance, just the clear and quiet self-belief that, to be frank, ought to be a given in any player who wants to take the major decisions in the cauldrons of Test rugby.

He is a bit young for a comeback, but it feels like one anyway. "It was frustrating when I wasn't involved in the Six Nations," he says quietly. "I knew at that point I was fully committed to Scotland and I was 100% behind my decision but I also knew that being involved in the team again was down to me, to the work I put in on the quality of my play.

"I had to make sure my level of play with Bath and my level of training when I was up with the squad was at the necessary standard to earn a place in the squad and in the team." In the tumultuous sequence of events around the Tonga game, there was a suspicion that Heathcote would be tarred as Robinson's project player – unwanted by Scotland and unavailable to England. Did he fear being caught in limbo, the rugby equivalent of a stateless person?

"I guess so," he shrugs. "When he [Robinson] left there was a lot of uncertainty among the players, not knowing what would happen in the months leading up to the Six Nations. But as soon as I was back involved in training I knew what I had to do." With the rugby public's attention focused on the Six Nations at the time, it went almost unnoticed that Heathcote delivered a superb all-round performance in ushering Scotland A to a 13-9 victory over their English counterparts on a dismal night at Newcastle's Kingston Park in February.

It was a reminder of the quality Robinson had identified in the first place, and a large dollop of particularly sweet icing was added to Heathcote's cake by the fact that George Ford, his opposite number, had a stinker for England that night.

Heathcote wouldn't put it that way himself, but Ford has been his rival and nemesis all the way through age-grade rugby, so putting one over on him was one of the more satisfying moments of his career.

Since when there has been an intriguing twist, as Ford has now signed for Bath. And as his father, Mike Ford, just happens to be on the Bath coaching staff, things maybe don't look so good for Heathcote after all. "Mike is a really professional guy," he says, perhaps just a tad too defensively. "He's made it clear there will be competition.

"We will go into pre-season and compete for the shirt and whoever is performing best will get it at the start of the season. Throughout the season we will both be given opportunities to play; whoever is performing best will probably be starting."

But back to Scotland. Or rather Durban, where Heathcote will wield the conductor's baton from the first minute of this afternoon's match against Samoa in Kings Park Stadium.

Intriguingly, Johnson has chosen Peter Horne as bench cover for the fly-half berth, a move that could signal a significant change in thinking at Murrayfield.

After years of speculation over whether Ruaridh Jackson or Duncan Weir (or even Greig Laidlaw) would be running Scotland's show for the next few seasons, could the battle for the No.10 shirt really be between Heathcote and Horne?

The Bath man takes the diplomatic position. "I think all the 10s who are in the running at the moment see it as a position they can nail down and make their own," he suggests.

"It is good there is that competition among three or four of us. It means we will all have to work really hard and that will bring on everyone's game. Looking forward to the World Cup, it is good to have guys competing for positions and pushing each other on."

Maybe so, but it would also be good if one of them could nail the position down, at least for a season or two. Heathcote has the chance to stake his claim today. He has travelled a rocky road on his rugby journey to date, but this could prove to be the most significant game of his life.