Hearts are due £625,000 from Andy Webster after the Scotland defender cut short his contract before joining Wigan Athletic, Fifa has decided.
Andy Webster is on loan with Rangers
But world players' union Fifpro has hailed it as a victory for the player - the first to use a new clause to leave in the third year of a four-year deal.
And Scottish union boss Fraser Wishart says more players will follow suit.
"The way Fifa put this out, it was as if Andy did something wrong, but he has been completely vindicated," he said.
Fifa said that the 25-year-old had broken his contract "without just cause", suspended Webster for the first two matches of next term and will investigate his agent, Charlie Duddy.
Webster exploited Article 17 but was four days late in giving the appropriate 15-day notice.
The role played by the Scottish players' agent, Mr Charles Duddy, in the breach of contract requires further investigation
Agent Duddy has refused to comment on Fifa's guilty verdict.
But Wishart said: "The players' union in Scotland has been advising Andy on his case for some time now after he was told by Hearts they would not play him unless he signed a new contract.
"We are pleased that a precedent has been set that will enable players across the world to have greater opportunities and rights within their conditions of contract.
"Fifa do not want players using this rule and that's why they have spun it this way.
"It was always going to be the case that Hearts were due compensation, but he was entitled to do what he did."
Fifpro public affairs executive Tony Higgins said: "FIFPro is delighted that the principle has been set that a player can now, under certain circumstances, cancel his contract, if under 28, after three years and, if over 28, after two years.
"We are reviewing the mechanism that was used to calculate the fee and the justification of the fee itself."
The players' unions have organised a media conference, to be attended by Webster, for Tuesday.
Fifa reported that its dispute resolution chamber "found Mr Andrew Webster guilty of having breached the employment contract without just cause outside the protected period and condemned him to pay Heart of Midlothian the amount of £625,000 as compensation".
Wigan, who signed Webster in August, were not found to be at fault.
"The role played by the Scottish players' agent, Mr Charles Duddy, in the breach of contract requires further investigation by the competent authorities," world football's governing body added.
"Therefore, the matter will be forwarded to the players' status committee for investigation and decision."
Webster left Hearts at the end of last season and the Edinburgh club were demanding £5m in compensation.
He made just four starts and one substitute appearance for Wigan before moving to Rangers in January.
However, injury has prevented him from making his debut for the Glasgow club, although Rangers are keen to make the transfer permanent.
It is unclear whether the £625,000 - which reflects the wages for the final year of his contract - will be paid by Webster, Wigan or Rangers.