Since rugby sevens debuted at the Olympics last year, a clash in regulations between World Rugby and the International Olympic Committee created a loophole in the eligibility system.
This loophole allows players who have represented either their country's top or second-tier XVs team or senior sevens team to switch allegiance to another nation, provided they have a passport for the second country and have completed a three-year international stand down.
Once the stand down is completed, players must partake in an Olympic event (which includes qualifying tournaments and the 2018/19 World Sevens Series) to make themselves eligible for their new nation at all levels.
Since the discovery of the loophole in 2014 few players have taken advantage of it with Tim Nanai-Williams being one of the only high profile cases.
Recently, however, a few players have announced their intentions to do so. We take a look at 10 superstars who could turn out for another country at the 2019 Rugby World Cup.
Ma'a Nonu - Samoa
Nonu will go down as ene of the greatest All Blacks of all-time after winning 103-test caps for the All Blacks.
The rampaging midfielder would be a prized asset for Manu Samoa with his well-crafted all-around ability. Nonu last played for the All Blacks in the 2015 Rugby World Cup final, meaning he - at the age of 36 - would be available to partake in an Olympic event for Samoa as early as the opening leg of the 2018/19 World Sevens Series in Dubai.
Manu Tuilagi - Samoa
Tuilagi is less likely than the other players on this list to make the switch but should he decide to switch the white of England for his nation of birth, he could form half of a formidable midfield combo with Nonu.
Renowned for his sheer power and blockbusting runs, constant injuries and suspensions have kept the 26-year-old out of England's squads in recent international windows. He most recently played for Eddie Jones' side against Wales in last year's Six Nations, which means he could turn out for Samoa's Olympic qualification campaign midway through the 2018/19 World Sevens Series.
George Smith - Tonga
The Wallabies legend amassed a total of 111 test caps over a 13 year period, where he established himself as one of Australia's greatest flankers.
Smith last pulled on the green and gold jersey in the final test of the 2013 British and Irish Lions series, meaning he met the stand down requirements in June last year.
Should he look to pursue a World Cup spot with the 'Ikale Tahi in 2019, he would have to do so at the grand old age of 39.
Victor Vito - Samoa
The former Hurricanes and All Black loose forward won Top 14 Player of the Year for his efforts during the 2016/17 campaign for La Rochelle.
Vito would become available at the same time as Nonu. The star looseforward has also expressed his interest in making the switch but has said: "I made my bed with the All Blacks so I wouldn't want to take away the opportunity or development of a player who deserves it more, but I would love to play for Samoa."
Digby Ioane - Samoa
The former Reds & Crusaders winger would follow in the footsteps of his father Natu if he turned out for Samoa, with the older Ioane playing one match for his homeland against the Maori All Blacks.
The 32-year-old's last appearance for the Wallabies came against the British and Irish Lions in 2013, meaning he has already completed his three-year stand down, making him or Samoan selection as soon as their Olympic qualification campaign begins.
Charles Piutau - Tonga
The soon to be highest paid player in the world departed New Zealand two years ago at the age of just 23 with only 17 test caps to his name.
The 26-year-old has chewed through two-thirds of his three-year stand down, and could still join his older brother Siale in representing the 'Ikale Tahi in future seasons.
Piutau has also expressed his interest in playing for Tonga at the Rugby World Cup.
Isaia Toeava - Samoa
One of the youngest All Blacks debutants ever, Toeava never really quite reached the potential many envisaged him to have.
The Moto'otua-born utility back won himself 35 caps for the All Blacks in addition to a 2011 World Cup title before jetting off overseas five years ago.
The 31-year-old's three-year stand down was completed in 2014, meaning he could have elected to represent Samoa in the previous Olympic qualification cycle for Rio 2016.
Frank Halai - Tonga
An electric winger who formerly played for the Blues, Halai became a one-cap wonder in 2013 when he made his one and only test appearance for the All Blacks against Japan in Tokyo.
In 2015 when he signed a deal with the UK-based Wasps, where he continued his explosive form by scoring 12 tries in 25 matches.
Now at Pau club in France, Halai has also expressed his interest of playing for Tonga to national coach Toutai Kefu, where he would undoubtedly make an instant impact.
The 29-year-old met the three-year stand down prerequisite in November last year.
Joe Rokocoko - Fiji
The joint record holder for most test tries scored in a calendar year (17), Rokocoko was one of the most electrifying talents in world rugby when he burst onto the international scene in 2003.
The Nadi-born wing, who now plys his trade at Racing 92, sits second-equal on New Zealand's all-time try-scoring list with 46 five-pointers in 68 outings.
His three-year international stand down was wrapped up in 2013, meaning he could make an appearance for the Olympic champion Fiji sevens side as early as next year.