Bernard Jackman says Ireland's match-up with the All Blacks in Chicago demonstrates how hard it is for rugby to break into the US market, but World Rugby dismissed any notion that World Cup 2031 will be pulled from the States.
The former Ireland hooker and RTÉ Rugby pundit was in Illinois to cover the game at Soldier Field, which Ireland lost 26-13.
In a sports-mad city, rugby is a minnow compared to American football, basketball, baseball and ice hockey and soccer, and Jackman reflected on his experience and how it could affect the 2031 World Cup, which was awarded to the US in 2022.
He first referenced a promotional segment on CBS television with New Zealand Rugby CEO Mark Robinson on Thursday.
"It blew me away, CBS, it was great to get the access for rugby to be talked about on a big TV show but there was a panel of three presenters and two rugby experts, one of whom was the CEO of New Zealand," he said on RTÉ Radio 1's Sunday Sport.
"I could see it on his face; he was shocked at the level of knowledge of what the game was like.
"The basic thing was 'it’s the NFL without pads’ but apart from that he was trying to explain that you can’t pass the ball forward.
"It’s a minority sport over here, some people will argue it’s a minority sport around the world compared to football and cricket, I understand that.
"The World Cup is due to be here in 2031 and that is an opportunity to grow the game but there is a lot of work to be done.
"MLR [Major League Rugby] has just lost two teams that have gone out of business.
"It's struggling and to be honest, there’s a feeling that they may have to pull this World Cup from the US in 2031 because the World Cup is so important to World Rugby, in terms of revenue.
"That effectively finances them for the next four years.
"If there is a chance that this won’t make money or could lose money, you could see a last-minute change to another country who is willing to guarantee a profit like the French did for the last World Cup.
"We’ve been so lucky the last couple of World Cups, Japan [in 2019] did an unbelievable job hosting it.
"Stadia were full, but the infrastructure around Japan...you can get around Japan on the train.
"Fans were able to move from city to city, the cost and scale of the States for fans is going to make it incredibly expensive and difficult.
"And yeah, to be honest, I am hearing strong rumours that there’s going to be a decision made in the next 12 months around whether they can go ahead with this or maybe postpone it.
"I wouldn’t like to see them not getting it. I’m just painting the picture of how little people know about rugby over here."
However, World Rugby, who last week revealed that 27 US cities have applied to host games, dismissed any notion that the tournament would not go ahead as planned.
"It’s full steam ahead, we are well advanced in planning," a spokesman told RTÉ Sport.
"There is absolutely no danger in pulling the World Cup from the US. It’s locked and loaded."
Speaking last week, World Rugby chief executive Alan Gilpin said: "This is an exciting and collaborative journey.
"Rugby World Cup 2031 will be more than a tournament. It will be a nationwide celebration of sport, community, and culture, reflecting the diversity and dynamism of the United States."
IRFU CEO Kevin Potts revealed last week that Ireland, who have played three standalone matches in the US in the last nine years, intend to play games there every year up to the tournament.
"I admire the IRFU and the All Blacks coming here," added Jackman. "Chicago is a great host city.
"I’m not talking about the game, we’ve all seen good and bad games but the actual production around it left a lot to be desired.
"The whole occasion was a letdown.
"The atmosphere pre-match, the build-up all week was phenomenal.

"The stadium got it all wrong, I don’t know what it was like on TV but not having the big screen working for the Tadhg Beirne [red card] incident, the length of time it took to get the decision.
"The stadium announcer wasn’t really familiar with rugby.
"The match itself wasn’t the quality you’d expect from two brilliant teams. The whole thing was a damp squib; the atmosphere died in the ground.
"It was an occasion that failed to live up to expectation and that’s unfortunate because it was a great opportunity to bring new fans into the game.
"Anyone watching that for the first time on US TV wouldn’t be massively encouraged to come back, which is a disappointment."
Watch Ireland v Japan in the Quilter Nations Series on Saturday from 12pm on RTÉ2 and the RTÉ Player. Follow a live blog on the RTÉ News App and on rte.ie/sport. Listen to live commentary on RTÉ Radio 1 Extra