The BBC reported that Fuimaono-Sapolu had compared the treatment of his team to slavery, apartheid and the Holocaust, but any such tweets appeared to have been deleted.
The Welsh waited a full week to play again after their near-miss against South Africa on September 11, while Samoa were forced to back up only days after dispatching Namibia on September 14.
"The most important game in our history and we get three days off while our opponents get a week," he tweeted the day after the Nambia match.
"Who's the genius behind this s**t?"
No apologies, no fear
Fuimaono-Sapolu openly engaged with supporters and critics on Twitter, and made no apologies for the ferocity of his tone.
A fan named Ian Hill sympathised with him, but suggested he cut back on his swearing.
However, Fuimaono-Sapolu's response was dismissive.
"You know what this feels like? To be shat on by IRB? Don't dare tell me that again!"
The BBC has reported the IRB's disappointment at the comments, and it is understood that he may face disciplinary action if he is found to have broken social media rules in the Rugby World Cup's code of conduct.
Fuimaono-Sapolu said he was putting his team's welfare before his own, and didn't appear to fear any repercussions.
"You can't get punished for speaking out against injustice," he wrote. with a smiling face emoticon for effect.
"That would be unjust."
Money, influence and the rough end of the pineapple
Herald rugby writer Wynne Gray wrote about the lopsided schedule the morning after New Zealand's 83-7 demolition job on Japan.
The All Blacks faced the Cherry Blossoms eight days after their opening match against Tonga, who themselves had only five days to prepare for their second match of the tournament against Canada.
"World Cup scheduling is all about money and influence," wrote Gray.
"It's no surprise which sides get the rough end of the pineapple so pool play can finish on time.
"Mark down USA, Canada, Namibia and Georgia for compressed schedules as well as Samoa."
"Bizarre rant"
Fuimaono-Sapolu has used Twitter to vent his spleen on rugby matters before.
In May he drew negative publicity in England, where he plays for Gloucester, after posting a series of messages directed at rival club Saracens.
The Daily Mail described his messages as a "bizarre Twitter rant" and noted he was concerned that he might be left out of Samoa's Rugby World Cup squad because of his political views.
- NZHERALD ONLINE