A group of around 50 hooded fans stormed the club's training facilities and beat up the players.
Portuguese side Sporting CP have been in the news quite a lot as of late following several reports of unrest, as well as feuding between the board, coach and players.
Last month, president Bruno de Carvalho claimed to have suspended 19 members of the first team after a Europa League loss to Atletico Madrid prompted a social media rift between himself and the rest of the squad.
And on Monday, more reports surfaced, with Portuguese sources stating that the president had suspended manager Jorge Jesus and his entire backroom staff following a meeting.
Sporting have since released a statement in which they refute the claims. But supporters remain irate as their club have missed out on a Champions League place with a third-place finish.
On Tuesday, a group of around 50 hooded fans stormed the club's training facilities and beat up the players, per O Jogo. They are also said to have ransacked the place, leaving several squad members, including Bas Dost, nursing injuries ahead of Sunday's Taca de Portugal final against Aves.
Various sporting "fans" broke into Alcochete, Sporting's training complex, and are alleged to have assaulted their star man, Bas Dost. No matter how disgruntled fans are, they should NEVER blame/assault the players. Pathetic behaviour. pic.twitter.com/cVrg91LXA1— Marino Peixoto (@Marinovpeixoto) May 15, 2018
Physiotherapist Mario Monteiro and his assistant Raul Jose were involved as well. And A Bola are also claiming that manager Jesus, Acuna, Rui Patrício, William Carvalho and Battaglia were victims too.
"Sporting is not this, Sporting can not be this," the club said in a statement following the attack.
"We will make every effort to establish full responsibility for what has happened and we will demand the punishment of those who acted in this absolutely pitiful way."
The Primeira Liga also put out a statement, branding the individuals responsible 'criminals'.
"The behaviors that are being reported by the press are regrettable and have no place in professional football. The perpetrators are not football fans, but criminals."
There were already reports of players looking to leave the club this summer. And if those claims were false, that's very likely to change given the current state of affairs.