Uruguay captain Santiago Vilaseca has underlined the stark contrast of rugby backgrounds between his 5,000-1 World Cup outsiders and Sunday's opening opponents Wales.
While Wales' entire 31-man squad of full-time professionals are ready to go in a pool that also features England, Australia and Fiji, Uruguay's amateurs face a Herculean task just to be remotely competitive.
"I work in a bank," said Vilaseca, who leads Uruguay into their first World Cup since 2003.
"After work, I arrive home at around 8pm, to start again at 7am the next day with training.
"I had to (forfeit) my salary during the past two weeks in order to play, and during the next two months I am not going to receive any money.
"Since we qualified for the World Cup, we started to train five days a week and balance it between our jobs and studies. It has been very good to train as professionals, every week, five days a week."
Uruguay, ranked 19th in the world, lost their last World Cup game 111-13 against England in Brisbane 12 years ago, and they are given little chance of making any impact this time around in arguably the toughest group in World Cup history.
Los Teros head coach Pablo Lemoine said: "We are very excited to be participating in a Rugby World Cup and to play in the Millennium Stadium, which is one of the most important stadiums in the world. We are focused on the match.
"Wales are a really strong team, and we are expecting it to be tough, but I have told the players that one of the most important things is that they enjoy it.
"As amateur players it is the best experience for them, and everyone has to build their own experience from it.
"For us, it will be an amazing experience, but we are not watching the performance of the other teams. We have a commitment to our rugby back home in Uruguay.
"We feel the support from the people and the press, and that helps us to grow as a team. We are trying to make rugby the second sport in Uruguay, and it is now played in all state schools."
Wales assistant coach Robin McBryde, meanwhile, fully expects Uruguay to thrive amid the atmosphere generated by an anticipated 70,000 crowd in Cardiff.
"It's the opening game of the World Cup for us, and the occasion itself gives you a bit of adrenaline. That should get you going, regardless of who you play," he said.
"Also, from our experience, the opposition do raise their game as well. Admittedly, they are 19th in the world, but we will not take anything lightly and we will show them the utmost respect.
"But having said that, it is all about us tomorrow and putting on a performance and living up to expectation. We created a little bit of momentum with that win in Ireland (last month), and we need to regather that momentum."