Millions of euros flow through the coffers of top clubs like Porto and Benfica, but Joaquim Evangelista, head of the Portuguese Association of Professional Footballers, warned the depth of the country's national sport is under threat due to poor management at smaller teams.
"The vast majority of professional clubs in Portugal had salary delays last season, with six-month delays in the most extreme cases," Evangelista, told Reuters .
"This has led to Portuguese and foreign players being unable to pay their rent and food, surviving thanks to our union," Evangelista said. "The situation is getting worse. I alert you that delays will happen again next season."
Filipe Falardo, a midfielder who was at Benfica and won nine caps for Portugal's youth teams but later dropped to second-tier clubs, said the problem was a recurring one.
"I've suffered it (salary delays) first hand. I've had to go to court because clubs don't fulfil their deals. It happens every year," said the 29-year-old.
Evangelista, also a board member of world players' union FIFPro, blames blind ambition and poor management for disrupting the lives of players and their families.
"Most Portuguese clubs live far beyond their means and don't make an effort to adjust," he said. "On the contrary, they think: 'If I'm successful, I'll collect revenues later so I'll take that risk'."
Portuguese clubs such as Olhanense, Naval, Vitoria de Setubal and Vitoria de Guimaraes were some of those hit by financial troubles.
Portugal's credit crunch and the deepest recession since the 1970s under an international bailout have made it even harder.
However, a Vitoria de Setubal spokesman said Evangelista's comments on salary delays only hurt clubs and the sport in Portugal.
"I'm surprised by Mr Evangelista's comments... Setubal likes to solve its matters internally, we explained our reasons and I regret that he made such a public statement," the spokesman said.
"We consider the matter over. We work with maximum discretion to solve the problems that unfortunately we have. It's not easy in any sector in Portugal these days."
In one of the most extreme cases, Uniao Leiria in 2012 fielded eight players for a top flight-match after 16 players filed collective resignation letters over late wages. The club has since been declared insolvent.
Around 30 out-of-contract players are taking part in a training camp organised by the union at the Estadio Nacional, just outside Lisbon.
Their mood seems sombre and the feisty tackles signal some level of the frustration they hope to end by catching the eye of the scouts watching.
"Football players are often labelled as millionaires but at the end of the day that doesn't really happen," said former Benfica hopeful Falardo. "Maybe the bigger clubs do pay big salaries but the others don't."
Outside of Benfica, Porto, Sporting and Braga, footballers in Portugal earn, on average, between 2,000 and 3,000 euros a month so payment delays can cause havoc in their personal lives.
Evangelista said that by the end of 2012 his union had distributed over 350,000 euros in support to hard-up players.
"Is this the professional football that UEFA promotes and that the Portuguese League wants? Enough is enough," he said.
Evangelista also blamed shortcomings in FIFA's financial fair play requisites for worsening the plight of some players, saying while the rules were welcomed, clubs could abuse some loopholes.
Portuguese clubs have a summer deadline to show they have paid all salaries to be able to play next season. They can submit pay slips or have players sign a declaration saying everything is in order.
Evangelista said many players had no choice but to sign the declaration even if they had not received all due salaries.
"Players want to keep their jobs, to play, to get the money they are owed. They sign off because there is no other choice, otherwise they will be punished." he said.
- Sports & Recreation