Sporting director leaves after fight with Liedson
"After the events between football director Ricardo Sa Pinto and Liedson the board has opened a disciplinary inquiry. Meanwhile, Sa Pinto has presented his resignation, which has been accepted," Sporting said on its website.
Sa Pinto and Liedson argued on the pitch after Sporting's 4-3 home win over second division side Mafra in the Portuguese Cup fifth round.
According to local media, Liedson was angered by Sa Pinto's berating of keeper Rui Patricio's performance. The pair continued their quarrel in the locker room, where they exchanged punches.
Sa Pinto, who played 177 games in two spells for Sporting, was appointed director of football in November 2009.
The 37 year-old, who ended his career at Belgian side Standard Liege in 2007 and was capped 55 times, was involved in another violent row in 1997, when he punched coach Artur Jorge for omitting him from the national squad.