Leading goal-scorer Bas Dost needed six stitches after being punched and kicked, while manager Jorge Jesus was head-butted and punched.

The club finished the season third after a 2-1 defeat at Maritimo on Sunday and just missed out on a place in next season's lucrative Champions League.

Players have this season been frequently criticised by chairman Bruno do Carvalho, who at one stage suspended 19 of them.

The players were preparing for Sunday's Portuguese Cup final, where they take on Alves, when the alleged attacks took place.

A statement on the club's official website read: "Sporting Clube de Portugal vehemently condemned the events registered today at the Sporting Academy.

"We can not in any way agree with acts of vandalism and aggression to athletes, coaches and staff of professional football, nor with attitudes that configure the practice of crime that in no way honour and ennoble Sporting Clube de Portugal.

"Sporting is not this, Sporting can not be this.

"We will make every effort to establish full responsibility for what has happened and we will not fail to demand the punishment of those who acted in this absolutely pitiful way."