The former Samoa centre has slammed the limited chances for Pacific Islanders at Super 15 clubs in Australia and New Zealand.
Wallaby and Kiwi Super 15 franchises have long convinced Pacific Islanders who are eligible to declare for Australia and New Zealand above their country of origin.
As Samoa climb the International Rugby Board rankings, now reaching seventh, increasing numbers of Super 15-based stars are pledging allegiance to the island nation's cause.
Fuimaono-Sapolu has called on Super 15 clubs not to overlook South Sea islanders for contracts simply for not pledging allegiance to Australia or New Zealand.
A Samoa XV studded with household names of European club rugby will take on Ireland at the Aviva Stadium on Saturday in autumn international action.
Former Bath and Gloucester centre Fuimaono-Sapolu thinks without chances in Europe for Samoa's stars, the national side would fall by the wayside.
"Thank God Europe have a broader taste for all styles of rugby and there are many Pacific Islands players, as well as players from many other tier-two nations, playing there," admitted the 33-year-old, now playing in Japan for Coca Cola West Red Sparks.
"Without that, without Europe, Manu Samoa and the likes would struggle to exist.
"If we operated rugby the way New Zealand and Australia do, the game would never grow."
Controversial playmaker Fuimaono-Sapolu invoked IRB wrath and even a six-month world-rugby ban, suspended for two years, after likening Samoa's scheduling inequalities at Rugby World Cup 2011 to slavery and apartheid in a series of explosive tweets.
Fuimaono-Sapolu is still fighting to push Samoa's interests forward despite the 2011 New Zealand World Cup proving the end of his international career.
The outspoken midfielder is frustrated by the calibre of Samoa's final two autumn international matches, against the French Barbarians in Clermont-Ferrand on November 16 and Georgia in Tblisi on November 23.
He continued: "The fundamental principle of the game is to include everyone; rugby is for all shapes, sizes and skill-sets.
"Currently, rugby is the opposite, exclusive.
"One day it will change, and that generation in the future will look back at today's elite group with disgust and disbelief and ask 'how did we let such narrow-minded selfish people run the sport'.
"People in Samoa are angry with the scheduling for this tour.
"Samoa are not playing against anyone ranked more highly, so how can we move up the rankings?"
Census Johnston leads Samoa's list of five injuries for Saturday's Ireland clash, but Northampton's high-quality scrum-half Kahn Fotuali'i captains the side.
Most eyes will be on ex-Osprey Fotuali'i's scrap with Ireland counterpart Conor Murray, but Fuimaono-Sapolu has tipped wing Alapati Leiua and flanker Jack Lam to cause trouble for the Irish.
He added: "The new players to watch out for on this tour are wing Alapati Leiua, and flankers Faafili Levave and Jack Lam (cousin of Connacht head coach Pat).
"All three are regulars for the Wellington Hurricanes and have only recently chosen to play for Samoa.
"There are many great players among those already established in the squad, but in particular number eight Taiasina Tuifua and hooker Ole Avei have been huge for Samoa."
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