Murray McCallum began the NatWest Six Nations campaign as part of the Scotland squad, making his international debut in one of world rugby’s most famous stadiums and on the weekend that it ends he will be playing in another, but it will be a very different environment.

The 21-year-old prop will be part of an Edinburgh team that will, on Friday, be playing at Murrayfield in what is in competitive terms a more important game than any of the Six Nations matches the following day. After all, whereas the contest is over for everything except the minor placings in terms of the international competition, play-off spots and with them a crack at the Guinness Pro14 title are still up for grabs with Edinburgh still very much in contention at this stage of the season for the first time in several years.

That has been reflected in the return to their squad of four players who were involved in Scotland’s training squad last week – Mark Bennett, Magnus Bradbury, John Hardie and Cornell du Preez – with Scottish rugby as a whole also set to benefit from a home victory in this cross-conference clash at the national stadium, since it would all but ensure that Glasgow Warriors finish above Munster in their table.

Having won his cap in Cardiff, then, it has been easy for young McCallum to place that experience in proper perspective and relish the opportunity to return to playing with his club as the Six Nations Championship has taken its course, rather than feel he is somehow missing out on the glamour.

“It is not really frustrating at all,” he said. “I’ve got experienced, world-class players ahead of me. I loved being lucky enough to get that experience of being part of the national camp. It was great to test myself against those boys and to get a run-out at somewhere like the Millennium was incredible, but it has also been great to come back here and get some really good game time – especially against the teams we’ve played like Ulster, Leinster and the Dragons.”

What that trip to Wales with the national side has given him is a taste for the big time and the belief that having been there once, he has a better idea of what is required to get back there again.

“It has really just given me the confidence to really push on. I know it is not that far away. As a tight-head, it has been good to test myself against some really high-glass loose-heads, like Gordy Reid, who is down in the Premiership. It is great to see how other people operate and test yourself in different situations.”

It has also meant that on his return to Edinburgh McCallum has felt readier to offer a lead.

“I’ve not got the buffer I had last season of having just been chucked in from the academy. I’ve had my year of testing the water and just needing to do the basics to get through games, now it’s absolutely expected of me to step up and take on responsibility,” he reckoned. “I’m almost 22 so not really a child anymore, so I am absolutely expected to compete as hard as the guys in their 30s at the other end of their career.”

That understanding is indicative of a regime at Edinburgh which is rewarding form rather than reputations with competition for places driving up standards.

“Just the whole dynamic of the team, we’ve now got a winning mentality, I can’t tell you how much better it is coming back into training after a win, or even a narrow loss with a good performance,” said McCallum. “It is frustrating to lose but even when that happens we feel there is something there we can build on, rather than just having your head down in team meetings and hoping the coach doesn’t look at you. We’ve got some good results which fed confidence. Now we really want to go places, prove we are not just here to make up the numbers.”

Friday’s match will be a real test of that and McCallum is anticipating a Test quality work-out against a vastly experienced campaigner.

“I don’t know which boys they will have away with Ireland, but I think I’ll be up against Dave Kilcoyne, who I scrummaged against last season. He is a really experienced player and a tough, tough guy,” said the youngster.“They’ll have some experience in the team, whether it is old heads or boys not quite getting their shot with the national team, but it’s going to be a fair old battle against a physical side. So, we really need to man up and go at them, not sit back.

“Munster are one of the biggest teams in Europe, have been for years. These high pressure games are the ones that everyone really wants to be involved in. For me, it’s all learning. I’m not a kid anymore but I am still at the start of my career, so it is about taking on all these experiences to keep pushing forward.”