Ex-Wales skipper Dan Biggar says he endured a difficult week after his international career ended, admitting his retirement "knocked me for six".

Wales' 29-17 quarter-final loss to Argentina proved to be his final game.

"If I'm brutally honest I expected us to win that quarter-final, I don't think I was quite prepared for it to end so abruptly," said Biggar.

"When you lose in a quarter-final there's no hanging about for a third and fourth play-off. You basically pack your bags when you get back to the hotel and you check out and you're home within 24 hours.

"So for me it came as a bit of a shock and it knocked me for six a little bit. After everything I'd given to the sport for as many years as I had, I didn't really think that was how it was going to end.

"I remember just walking down the tunnel in the velodrome in Marseille after doing a lap and thanking the fans and that sort of hit me then because I knew that at that point there would be no more, that would be the last time that I'd walk back down a tunnel in a Wales shirt."

Biggar, who continues to play club rugby for Toulon, won the first of 109 caps for Wales as a 19-year-old against Canada in 2008 and also made three Test appearances for the British and Irish Lions. The 2023 tournament was his third World Cup.

"I've been around the block enough to know that storybook endings very rarely happen, but I also thought that the way that we went in that World Cup up until that quarter-final stage, I think we allowed ourselves to get carried away with that which is why it probably knocked the absolute stuffing out of me afterwards and it was such a huge, huge low really afterwards," he told BBC Radio 5 Live's 2024 Guest List programme.

"What I was more disappointed with was that I'd been in that group for a long time with lots of very good people from the management, staff, playing side of things," added Biggar.

"I felt like if we had won that quarter-final it would have given me a bit of a free-shot at a semi-final and a bit of a chance to know that I would be in camp for two more weeks and maybe plan what we were going to do for maybe the last meal in camp or the last time we go to the stadium.

"I think that was my real aim. I know that we were nowhere near as good a side as South Africa, Ireland, New Zealand and France but that's what I think I was robbed of a little bit, in terms of those couple of weeks of enjoying people's company with no real pressure going into a World Cup semi-final, which is bizarre really when you think of it.

"That was something that knocked the stuffing out of me a little bit that week and it was a really, really tough week to come to terms with after that."

Unlike the majority of the squad, there was no immediate return to Wales for Biggar after the tournament.

The Swansea-born player has been playing for French club Toulon since October 2022, though he did not stay in France to witness the climax of the tournament.

Instead he went on a family holiday.

"I jumped on a plane to Dubai and just got away because everywhere around me I was being surrounded by rugby and I just couldn't hack being around it really," said Biggar.

"With Dubai being three hours ahead, the games kicked off at nine o'clock in France [and] Dubai time it was 12 o'clock, so it gave me an excuse not to watch the games and just check the scores in the morning.

"I was definitely able to switch off from rugby for that week which was pleasing because the last thing I wanted to do was be talking about rugby, or watching rugby, or analysing the game.

"It was really important to get away from it and come back fresher."

Rugby in 'vulnerable state'

The 2023 Rugby World Cup in France was lauded as a huge success, with more than 2.4 million fans attending matches inside the nine venues used for the tournament and a further 1.6 million enjoying the games in rugby fan villages.

The French domestic game is also in robust health with La Rochelle and Biggar's Toulon the two reigning European cup competition title holders.

Biggar is well aware that the game is facing greater challenges on these shores and hopes 2024 will bring growing interest and fresh investment to the game in England and Wales.

"I'm playing in a league which at the minute seems miles apart from everywhere else in rugby in terms of the finances, the support," Biggar added.

"It's an absolute showpiece every week in fairness. You've got big stadiums, big crowds, big cities, big owners with deep pockets, which obviously helps in this day and age.

"You want big crowds, big occasions every week, and I watched a little bit of the Welsh derbies over Christmas and everyone [was] saying how great it is to have big crowds.

"For me it's a little bit fake really because you always get big crowds on Boxing Day and New Year's Day. Basically people are looking for an excuse to get out of the house and go to sporting events.

"What I would like to see is big crowds and big occasions every week and people turning out to support their regions, their clubs, whatever it is, because I've seen it first hand here how much of a difference it makes to everything - the occasion, the atmosphere, the match, the TV rights.

"Where we don't want the game to be is just standing still. I think it's so important that we continue to grow the game, continue to bring in new ideas, new venues, new audiences, everything like that."