For a man who has been joking about being in his dotage for years, Nathan Hines does a pretty good impression of a spring chicken, Peter Pan or just about any other symbol of eternal youth you can think of.

When he moved to Clermont Auvergne two years ago, the expectation was that Hines would wind down his career by becoming one of those redoubtable old codgers who trots on for the odd 20 minutes to close out a game. But there he still is, 36 years young, a central figure in one of Europe's top teams and regularly putting in the full 80-minute shift.

So it's a busy life for the man who represented Scotland 77 times before he retired from the Test scene after the 2011 World Cup. And yet this is the calm before a rather large and tempestuous storm. His diary for the first week of June is certainly not the schedule of someone who is taking things easy.

By then, of course, Clermont may well have got their hands on the Heineken Cup, for which they are priced 6/4 favourites.

Things then really start hotting up. On June 1, the final of the French Top 14 championship takes place, as does the opening match of the Lions tour to Australia, albeit a rather silly affair when the tourists take on the Barbarians in Hong Kong. That schedule might present Hines with a dilemma.

But there's more. The first week of June is also when his wife Leanne is due to give birth to twins. Just as well he's so famously laid-back about life. Or he is on the surface at least. Beneath that gentle-giant exterior is a ferocious competitor and one of the most effective enforcers in the modern game. And not the kind of fellow who takes setbacks lightly.

Like the one he suffered in June 2009. The Lions pack had just been humiliated in Durban, in the first Test against South Africa. Hines looked certain to replace Alun-Wyn Jones for the second Test, in Pretoria, but he was cited for a dangerous tackle in a midweek match against the Emerging Springboks, banned for a week and lost his chance. Simon Shaw was given the slot instead.

"He got man of the match," Hines remembers. "The bastard."

So there's some unfinished business there? "Oh yes," he replies. "There definitely is. I would love to get another chance to get the Test slot. But it's not for me to worry about. It's still a couple of months away and out of my hands. But yes, I was disappointed not to be part of the Test squad in 2009, and I would love to do it now."

Having retired from international duty with Scotland, Hines would be a surprise choice for the Lions squad, but his form at Clermont could easily earn him his place. "I wouldn't say no if I was asked," he says. "I'm certainly not unavailable."

All of which could put him in an interesting position. Hines' time at Perpignan came to a messy end in 2009 when he put playing for the Lions ahead of representing the club in the French championship final, so a compromise might have to be struck. Given his family situation, Lions coach Warren Gatland could easily justify any decision to allow him to join the touring party late.

But these are bridges still to be crossed. Of more pressing importance is Saturday's Heineken Cup quarter-final clash with Montpellier – Johnnie Beattie included – at Clermont's seething Stade Marcel Michelin ground. On paper, it should be a comfortable home win, but Hines is adamant that complacency should never be an issue.

"We don't have a swagger at our club," he says. "If you start acting like that you get shot down in flames. Obviously, we are confident that we can play well, but we are hard workers who just happen to be good players at the same time. Nobody lets anyone get ahead of himself. We're realistic and we know that no matter how much potential you have you can always be beaten by a team who are playing well if you are not."

For many years, Clermont's most notable, or rather notorious, distinction was their serial failure to win the French Championship. Ten times they got through to the final, and ten times they lost. That sequence finally came to an end in 2010, when they beat Perpignan 19-6 in a packed Stade de France. One of the heaviest monkeys in sport was finally off their backs.

Hines was not there through the gory years, but from the testimony of team-mates he appreciates that the culture of the club was changed by that success. "I suppose it was bound to make a difference. The pressure mounts on you, and the more you want something the more pressure you feel. Winning in 2010 just took some of that pressure off.

"I think they took a dip the following season, just took the foot off the gas a little bit. That was maybe a wake-up call, a reminder that you can't take things easy."

There are those at Leinster who say the worst thing the club ever did was let Hines leave for Clermont in 2011. He departed with a freshly-minted Heineken Cup winner's medal, having made a try-scoring contribution to the Dublin side's astonishing 33-22 comeback victory over Northampton. His absence was so keenly felt by Leinster last season that, after some wobbly performances in the Heineken pool stages, the Irish side were obliged to bring in Brad Thorn, the All Blacks lock, on a short-term contract to fill the gap Hines had left.

Ironically, Clermont were then squeezed out by a Thorn-inspired Leinster in a thunderous semi-final in France last season. Leinster, however, failed to reach the Heineken quarter-finals this season, while Clermont power on. If the French outfit go all the way and win the thing, Hines would become only the second player to lift the trophy with two clubs from different countries after Eoin Reddan, who won with Wasps in 2007 and Leinster in 2011 and 2012.

Can they keep focus? Historically, French sides have been guilty of concentrating on their domestic championship at the expense of European ambitions, but Clermont are firmly in the frame for both. Does Hines think the mindset has changed?

"I can't speak for any other club, but we are certainly targeting both and hold them in equal regard," he answers. "I think the Heineken certainly has more prestige in France than maybe it used to have. It is good to be champions of France, but being champions of Europe is a bit more. I think it's more recognised now as a title that French teams want to win."

And will those old legs of his stand up to it all? Clermont certainly think so, for rather than putting him out to pasture they have just extended his contract for another year. That, though, will surely be it for this rugby Methuselah.

Or maybe not. "It depends how I'm feeling," he says. "There are days when I just feel pretty old and beat up, but most of the time I still feel OK. On the other hand, with age comes knowledge, and you know your body better so you tend to take more care of yourself because you have to. As long as I'm playing well I'll want to go on."