William Carvalho, Gelson Martins and Bruno Fernandes ask to end Sporting Lisbon contracts

Three Portugal stars currently in Russia getting ready for the World Cup have told their club Sporting Portugal they will break their contracts, the club said on Monday.

The move is part of a continuing meltdown after the players were attacked and in some cases savagely beaten at their own training ground by a 50-strong gang of masked fans in mid-May.

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William Carvalho, Gelson Martins and Bruno Fernandes sent separate messages to the club, commonly known as Sporting Lisbon, saying they had a 'valid motive' to free themselves from contracts.

Sky Sports News understands Carvalho is a target for Everton, having previously played for new manager Marco Silva.

Other players who graced the green and white hooped shirts of Sporting had already informed the club of their intention to leave including captain and goalkeeper Rui Patricio and young hope Daniel Podence.

The club's coach Jorge Jesus also quit.

Twenty-three people were remanded in custody following the attack on Sporting's Alcochete training base in the Lisbon suburbs.

The incident came in the build-up to the Portuguese Cup final, which Sporting lost 2-1 to unfancied Aves to complete a miserable end to the season.

Sporting finished third in the table following a defeat at Maritimo in their final game of the season to miss out on a place in the Champions League qualifying rounds.