It is evident within seconds that Alun Wyn Jones is still seething. The sun is high in the clear blue Llandarcy sky but the Ospreys captain is tucked so far into his hoodie his face is barely visible. Any resemblance to the rampant Lion of three months ago is hard to discern. "Sorry, I'm struggling today," he mutters, pointing to the stone wall he is sitting on. "You've more chance of getting blood out of that."

Welcome to the hidden side of professional sport, where the intense pain of a sub-par performance can linger for days. The "dark place" currently occupied by the Welsh lock is directly traceable to last Saturday's disappointing 19–9 Heineken Cup home defeat to Leinster. To say Alun Wyn has taken it badly is a gross understatement. "It's easy to put a finger on what went wrong. We were crap. The errors we made were embarrassing. I use that word because I think it's right. Mistakes happen but I'm angry as well. Ultimately I'm the captain but if someone can't get themselves in the right state to play, it's not my job. If they don't want to come into work determined to be the best they can be, they're in the wrong job."

Heaven knows what his response will be if the Ospreys surrender limply again in Northampton this Sunday. The 28-year-old has captained Wales and the Lions, won 70 caps for his country and collected Grand Slams and Six Nations titles but the Leinster game snapped something deep inside him. "We seem to do pretty well in the Rabo but we can't do it in this competition. Every year I go to the launch and say: 'This year we're going to make a fist of it.' I've done it for the last four years and made myself look a right twat. The sadistic side of me says that sometimes it's better to lose than be the shower of shite we were [last weekend] and capitulate. I'm using strong words for a reason. We're a lot better than we showed at the weekend."

Time to at least try to lighten the mood. If the Lions tour proved anything it was the status of 'AWJ' as a magnificent warrior, his key role as captain for the decisive final Test victory in Sydney guaranteeing a lifetime of back-slapping and widespread respect. He must have enjoyed it but, right now, sadly, the invitation to reminisce just makes him cross again. "I've done it to death. Looking back, looking back … I don't want to live off that for the rest of my career. I've got other things to do, other things to achieve."

OK. Deep breath. The carefree, mischievous Alun Wyn who kicked off our first interview in 2009 by asking if they sell the Guardian in Wales is clearly elsewhere. But there is a big difference between an irritable interviewee (to his lasting credit a politely apologetic email turns up 24 hours later) and someone clearly being driven to distraction.

Welsh international rugby may be healthy enough results-wise but the regions are feeling increasingly hen-pecked, lacking money and the ability to retain their major drawcards. Jones is a proud Swansea son – "This is home" – but he is in the final year of his contract and knows life-changing financial opportunities exist in France. "Can you blame people if they get played to death over there for a lot of money? OK, it might be a shorter career but you're making a lot of money." What if the Ospreys do not – or cannot – share his hunger for more trophies? "If I don't do it here I may do it somewhere else. If it can be done here, great. If not, I've got to move on."

He declines to be more specific, having already received "a tweet from some bloke calling me a mercenary" for even floating the possibility of going to the Top 14. Along with many in Wales, though, he fears the Welsh Rugby Union's attempt to set aside funds to keep its Test players at home "could potentially be too little, too late" for all parties.

"It's great having a good academy but if you can't pay the players you're producing what's the point of it? You might as well use the money on bringing in marquee players. There's no sustainability."

His own fleeting descent into corporate-speak, though, sparks another sudden outburst. "It really gets my back up when people start using business phrases – 'sustainability', 'the brand' etc – about rugby. There are real people on the pitch. We're not commodities. Well, maybe we are to some degree but it's the team which creates business. Some people don't appreciate that. Rugby should take priority but it's becoming diluted by money and business. If I was a footballer getting paid a ridiculous amount I probably wouldn't be complaining but, in a way, that makes it simpler. He who has most money will have the best team. I don't think rugby should go that way but it's in danger of doing so."

It is starting to feel like a counselling session, if not a cry for help.

Everywhere you look in Welsh regional rugby, not least Cardiff Blues' first-half effort in Exeter last weekend, there appear to be flashing amber lights. Perhaps life would have been simpler had Alun Wyn been born English? A thin smile finally flickers across his lips. "I'd have moved to Wales. Because I'd rather be Welsh." You suspect he may have some interesting conversations with Josh Lewsey, the former England player who has just started as Wales's head of rugby, before the 2015 World Cup.

It is also legitimate to wonder if beating the hosts, England, in that tournament might, for him, rival the Lions for inner satisfaction? "That's definitely up there [as an ambition]. But if I say that in the Welsh press there'll be a headline 'Wales are going to win the World Cup'. That's why I'm very cautious what I say to a lot of people."

His relationship with sections of the Welsh media is, at best, strained. "I don't trust some of them, to be honest with you. I've been in both the best and worst Welsh teams ever within the same four-month period. I'll say what I mean, not what they want me to say." Would he care to elaborate? "If I gave them a jigsaw puzzle piece they'd be happy to carve it to make it fit."

By now one thing should at least be clear: this is a man who does not just have a law degree but also knows his own mind. Thank goodness; the pro game needs moreof them. Above all, though, a fierce competitor burns bright, keen to mix it with Lions mates such as George North. "You have a wry smile when one of them puts a shot on you but no one's giving a yard. It increases your respect for people when you've played with them and they've helped you achieve something." If the Ospreys nose-dive again, it will not be Alun Wyn's fault.