Muntari tried to draw the referee's attention to the Cagliari supporters who were discriminating against him because of his skin colour. Rather than halting the game and calling for an announcement to be made, the referee instead showed Muntari a yellow card, at which point the player left the field out of protest, resulting in an automatic one-game suspension.

The Lega Serie A's disciplinary committee confirmed on Tuesday that some racial chanting had indeed been heard but said they would not be taking any action because it had only come from a minority of the fans.

The disciplinary statement read: "Considering that the in-any-case deplorable racial discriminatory chants were only heard due to the fact that the fans were participating at the time in a silent protest, and that these were made by a total number of around 10 supporters, which is therefore less than one percent of the number occupying that sector of the ground (approximately 2,000), there are no grounds to punish this behaviour.

"It could not really be heard and, furthermore, was not heard by the referee (as mentioned in his match report)."

Sulley Muntari walked off the pitch after being booked for complaining to the referee about racial chants from Cagliari fans.

Players' union FIFPro on Tuesday called on Italian authorities to rescind Muntari's yellow card and ban.

"Muntari was well within his rights to approach referee Daniele Minelli, as the first point of reference, to make his grievances known and seek a solution," a FIFPro statement said. "Players should feel comfortable bringing any issue to the attention of the referee, especially one as significant as allegations of racism in the workplace.

"No player should ever feel the need to take matters into his own hands, as Muntari clearly felt obliged to do, by abandoning the match or taking spectators to task for inappropriate behaviour."

While Cagliari will not be punished for their fans' racially discriminatory behaviour, both Inter Milan and Napoli were threatened with partial stadium closures -- suspended for a period of one year -- for similar conduct by their fans at the weekend.

A larger group of Inter fans -- estimated to have been 80 percent of the approximately 7,000 spectators in the secondo anello verde area of the San Siro -- were heard racially insulting Napoli's Kalidou Koulibaly, while a similar number of Lazio fans were estimated to have made racial insults towards Roma's Antonio Rudiger at the Stadio Olimpico.

Both clubs will see the suspended sentences activated should there be any further acts of racial discrimination at any of their home fixtures in the next 365 days.