He learned its nuances from the lowest levels of American life to the highest: from the broken bottles and scruffy playing fields of Gonzaga High School in the perpetually troubled downtown of Washington DC, to the rare air of Aspen, Colorado, winter and summer playground of his country's mega-rich; amidst the sun and sybaritism of San Diego, California; and now in Bath, heartland of the English rugby premiership.
As with any practitioner of a second language, the results can amaze and amuse. Lyle loved basketball - the catching and the passing, not the shooting - and elements of that have carried over to this game, with one- handed flick passes and attempts at sleight of hand that have confounded his team-mates on the United States Eagles as often as the opposition.
At 6ft 4in and 17st 6lb, and with his best years in front of him, Lyle is living proof of what believers in America have always said of their rugby players, or at least the pool they are drawn from: they are unsurpassed as athletes, if only they would give the game a try. That they don't is less the result of unwillingness than ignorance. "Rugby exists outside the sporting mainstream," admits Jack Clark, USA Rugby's general manager of national teams, of the code in his country.
Way outside. When the Denver Barbarians won the US Superleague final in June against the Belmont Shore club, of Long Beach, California, a single television camera recorded the celebrations. The result was announced in the furthest reaches of the sports section of the Barbarians' local daily, the Rocky Mountain News, three days later.
The game attracts students from New Zealand who take up college scholarships, and South Africans in their late 20s, hoping to set themselves up in business and start a new life. The games are played on high- school grounds - not the stadiums, surrounded by grandstands, but the practice pitches - on undulating, reclaimed parkland, at the foot of ski runs in Vail, Colorado, and near the war monuments in Washington.
Few clubs have dressing rooms to change in, fewer still lights to train under. They play in tournaments like the Cowpie Classic, in Montana, the St Valentine's Day Massacre, in the February snow of Breckenridge, Colorado, and the Midnight Madness assembly, in Nevada in high summer.
They play with enormous enthusiasm, but not much fluency. You're more likely to find a pacifist at a gun rally than a sweeping back-line movement at your average club match. And that, says Lyle, helps explain, if not excuse, results such as last month's 106-8 hiding by England.
Taking Test level as Tier One, and then descending through Super 12, provincial and premiership rugby, and then the club competitions of Australia through to Japan and Argentina, he finally arrives at his point of origin and departure, American club rugby. "We're eight to 10 tiers below what it takes to compete at Test level," Lyle says. "That's how big the jump is."
This is the impetus behind the new national competition, alluded to in a Sunday newspaper report in mid-July. That story claimed that USA Rugby was about to launch a national professional league, funded by Rupert Murdoch, and with international players as the backbone. The story was correct inasmuch as Murdoch, through his BSkyB network in Britain, and to a lesser extent the Fox network in the US, has been a principal supporter of USA Rugby. Likewise, there are plans for a new national semi-professional competition, which would be city rather than club-based. Beyond that, Clark has dismissed the story, while admitting: "There will probably be some foreign expertise involved."
Ultimately, that would be directed at athletes with a similar cv to Lyle: outstanding college football players on the fringe of NFL careers, ambitious and gifted enough to believe they can make it, but realistic enough to understand that dream is a year- to-year proposition at best.
Such was the decision confronting Lyle in 1996: a career in the newly- professional sport of rugby with Bath, or a single-year, bare-bones offer from the Minnesota Vikings, for more than twice the money he could make in England. "I was confident I could make the team," Lyle said of the Vikings' offer, "but it's so businesslike. Your top-end players make all the money, and the rest are recycled, year in and year out."
There was also the question of lifestyle for a young man whose father's journey towards a two-star generalship in the US army had taken them through more than a dozen towns across America, as well as three cities in Germany. "The life experience in American football is you live and base yourself in one city and travel around to a couple of other cities. You play American football and that's life. You get a lot of publicity and a lot of money if you have longevity, but the other things you do in life are up to you. Rugby union is a lifestyle, much more than being a professional athlete."
That lifestyle has deposited Lyle and his American team-mates in Ireland, their base for what will very likely be a short stay for the early stages of the World Cup.
The irony of this international event is that the planet's self- proclaimed and grudgingly accepted leader in diplomacy, commerce, and technology will have essentially Third World status. Lyle knows it and accepts it, up to a point. "We have to hope a team have a bad game and we perform out of our skins to compete with the top five," he says. "It may be one in 10, or two in 10, that we could beat Ireland.
"I was definitely embarrassed to lose that game [against England], but maybe it was a place we had to go to be aware of ourselves as a team."