When USA Rugby departed the 2015 Rugby World Cup after a winless pool stage, they did so with a very clear message: Amateurism just isn't going to cut it.

"One of the things that we know is that to be in the top eight [teams in the world], we need a fully professional team," then-USA Rugby CEO Nigel Melville said at the time. "All the teams with amateur players failed to make the top 8 -- Georgia, Namibia, Canada, Romania -- and even some of those with fully professional teams did not make it. This has to continue to be a focus moving forward." To Melville's point, 11 of the 31 players selected for USA's 2015 Cup squad came from amateur setups.

Their 2019 World Cup campaign in Japan begins Thursday against England and doesn't get all that much easier from there, with France and Argentina making it three Tier 1 nations in Pool C -- one of two pools to have three such teams -- and then Tonga, ranked 15th in the world, completing the group. The USA, by comparison, are ranked 13th having been 16th at the beginning of the last World Cup. But the Americans come in with well-earned confidence that they can turn heads and gain respect from the rugby world.

The vision in 2015 was to establish a professional rugby league in the United States. The initial attempt, Professional Organization (PRO) Rugby, flamed out in one year, giving way to the much more promising and robust Major League Rugby.

American rugby fans would be remiss if they didn't remember the one-year disaster that was PRO rugby. Bankrolled by a businessman with little rugby background, the failed experiment featured more lawsuits than it did teams. Many stemmed from non-payments by the league office, from players to coaches to local dining establishments.

USA fixtures - Pool C (All times ET, world ranking in brackets) Thursday Sept. 26 - 6.45am England (3) vs. USA (13) Wednesday Oct. 2 - 3.45am France (7) vs. USA Wednesday Oct. 9 - 12.45am Argentina (11) vs. USA Sunday Oct. 13 - 1.45am USA vs. Tonga (15)

MLR was built with more of a grassroots approach in mind. Each franchise has individual ownership groups, so there is no single financial judge, jury and executioner. Entering Year 3, it continues to expand for the second consecutive offseason adding teams from Washington DC, Atlanta and Boston respectively to make it a 12-squad league. The teams all hail from cities with strong rugby bases. Natural fan bases have followed, with some of the top amateur talent from the local clubs joining the professional ranks.

Its standing on the national squad has been felt with 13 of the 31 players selected to play in Japan in the MLR, and now all of the USA players play professionally somewhere in the world.

It has made a sizeable difference, says veteran No. 8 Cam Dolan, who also plays for the MLR's New Orleans Gold, and appeared in all four of USA's 2015 World Cup matches. "The fitness, strength and explosion levels into contact are all much greater now. Before you had to come into camp and then get fit. Guys had full-time jobs, and were only training with their clubs on Tuesdays and Thursdays. You had half the guys coming from amateur setups and half the guys coming from professional setups. It was just tough to get everyone on the same page."

Every competitor wants to win every game, but the winless 2015 campaign was not much of a surprise, according to USA head coach Gary Gold. "When I first met up with the guys in 2016, a handful of the players who'd been called into the camp hadn't played rugby in three or four months," Gold explained. "Unfortunately when you've got that and you're playing against Tier 1 teams, you're not going to advance. It's not possible for how teams are conditioned today in the professional era. The advent of the MLR in America has made a huge difference."

The long-term staying power of a professional league in any sport is always tenuous in the early going. But as the MLR continues to expand entering its third season, there are encouraging signs that this league will find and keep sure ground. The results of three years of domestic professionalism are already being felt on the national side.

The improved standard and fitness was on display to full effect in June 2018, when the Americans won 30-29 against Scotland, one of the teams that had beaten them at the last World Cup. The Americans' resolve was tested throughout last year's match in Houston, coming back from deficits of 21-6 and 24-13. It had to hold onto its slim lead for 20 minutes, bending at the end by allowing a Scotland try at the death. However, the conversion attempt from Blair Kinghorn sailed wide, and the Americans had their first win over a Tier 1 opponent since defeating France in the Olympics in 1924.

The establishment of Major League Rugby has been a major breakthrough for rugby in the United States, and has helped produce a fully professional squad for the first time at this Rugby World Cup. Leslie Plaza Johnson/Icon Sportswire via Getty Images

Dolan credits the fitness provided by a team that is now full of professionals for making the difference.

"Before, we'd hang on with teams for 40-50 minutes," he said. "Then we'd hit that 55-minute mark and they'd pull away. Now you're seeing us excel at that 60-minute mark, flipping the script, pushing teams for the full 80 minutes."

The run the Americans have been on the past three years shows it was no fluke. Rather, it's a team on the rise, one on its surest footing since it took gold in those 1924 Games. In the four years since the last World Cup, the Americans have extended an unbeaten streak against their former tormentors from the north, Canada, to 12 matches. In its final World Cup tune-up on Sept. 7, USA ran its winning streak to six games, with a draw breaking up a five-gamer that ran from 2014-17. Before that, it was Canada who owned the rivalry with a seven-game win streak.

USA has also flipped the script in the Americas Rugby Championship, the top-level tournament for teams from the Americas. The competition was once dominated by Argentina, but USA has won two out of the past three championships. The Pumas regained their crown this season, with USA settling for third. Third was also the result for the Americans in this year's Pacific Nations Cup. It was the first time the Americans had participated since coming in fifth in 2015.

And yet, for all the preparation, all the training in the heat and high altitude of Denver these past 10 weeks, and the encouraging signs seen in international play, it still may not be enough for the Americans to advance out of pool play in Japan. In spite of a nation back home so accustomed to winning (by comparison, consider the expectation sitting on the USA's Olympic team in Tokyo next year) progress could be just fine for Gold, pending the standard of play.

"We really want to go in there and be competitive. We're absolutely not going to give up against any of the teams we're playing," Gold explained. "But we'd really like the rugby supporters in the United States to see a team that's got a lot of courage, that is prepared to go toe to toe with the best teams in the world, and really can make them proud.

"If that means the scoreboard ends up going in our favor, that's wonderful. But if it doesn't end up that way, after 80 minutes of rugby we want those teams to feel that they were in a real fight. That they played against a team that was well organized, that played for each other, and played with a lot of heart."

The United States lost to Scotland in the 2015 Rugby World Cup, but exacted revenge last summer with their first victory over a Tier 1 nation since the 1924 Olympics. Jan Kruger/Getty Images

In short, the Americans hope to be this year's version of the Japan team that shook up the 2015 Rugby World Cup. Few could forget Japan's historic win over South Africa on the second day of the tournament, but even two other wins by the Brave Blossoms was not enough to see them advance to the knockout phase. Yet they were a primary story coming out of that tournament, and gained the respect of rugby fans, analysts and experts worldwide. That is the path the U.S. hopes to follow.

"We're going there to compete. We want to show the world how far we've come since the last World Cup and show the world what we're capable of," said Dolan. "We back ourselves and are confident in our abilities. I think you have to be, I think if you're not you are setting yourselves up for failure. The boys are ready to go."

Alongside the increased physicality and strength that comes with full professionalism, Gold and his staff hope to add the mental acumen with the adaptive and flexible game plan needed to make the difference in Japan.

"I think we've gone from promising a brand of rugby, to being more pragmatic about what we do, and we've tried to play to our strengths," Gold said. "Are we going to play an incredibly expansive game? Probably not yet. But there are aspects of the game that we've identified we're quite good at, and we can focus on that and build. We've decided we'll stay away from the things that we probably can't go toe to toe with the best teams in the world and we try to focus where we can go toe to toe."

One of the areas Gold will build around is at fly half, the position manned by AJ MacGinty, who plays for Sale Sharks in the Premiership in England. It was MacGinty who spotted territory and recovered his own kick before offloading to flanker Hanco Germishuys for the game-winning try against Scotland last year.

On top of the innate abilities of MacGinty will be the experience of wing Blaine Scully and Dolan (96 caps combined), with a dash of elite athleticism borrowed from the Sevens side sprinkled in. Sevens is where American rugby fans can have their appetite for wins satisfied, and a number of the team that finished runners-up in the Sevens World Series are switching to the 15s side for this World Cup. One is Martin Iosefo, the winger who scored the winning try against Canada recently. That move started with Iosefo powering over Canadian back rower Matt Heaton, and ended with him outpacing the rest of the Canadian defense.

It was not the United States' prettiest win in recent memory against the Canadians, but it displayed the confidence Dolan has seen his team play with since the last World Cup.

"That's something we've drawn from the Scotland game. We know, no matter how much time is left in the game, we still have a chance. Then when we do have that lead late, we keep our composure and stick to task," Dolan said. "I think the good thing about this team is, regardless of who we are playing, or what competition we're playing in, the preparation is all the same, the mindset's all the same. I don't think that's going to change much in the World Cup."

With the athletes it has at its disposal, the United States has long been billed as "sleeping giants" on the international stage. Now, with those athletes in fully professional environments, the question is can they match up consistently with the best teams in the world? With three of the top 10 teams in the world awaiting in Pool C, the opportunity to answer that question is right in front of the Americans.