Seven Sporting Lisbon players have reportedly succeeded in terminating their own contracts at the club.
According to BBC Sport, the Portuguese Players' Union has stated that the players - including four members of Portugal's World Cup squad - cited "just cause" as a reason for the termination.
The report also states that a court will have to establish the existence of just cause, which means that the players would have had a legally sufficient reason for their actions.
The news comes after a group of 50 masked fans attacked players and staff in May following the club's failure to qualify for the Champions League, leaving forward Dost injured.
Sporting president Bruno De Carvalho also threatened to suspend the entire squad after they lost to Atletico Madrid in the Europa League, although he deleted the post on social media and most of the players featured in their next game.
The Lisbon-based outfit, one of Portugal's biggest clubs, finished third in the Primeira Liga table last season.