The 32-year-old former Portsmouth, Inter and AC Milan midfielder, was booked as he appealed to the match referee to stop the game with Cagliari.
Muntari claimed he had been abused by a section of the crowd, and subsequently left the field in protest, only to be handed a second yellow card.
He has since been handed a one-match ban for his actions while no action will be taken against the racial perpetrators as the league ruled that with only "approximately 10" supporters involved, which is less than 1% of the Cagliari supporters in the stadium, they are not required to impose sanctions.
World Football Players' union Fifpro earlier said in a statement: "Muntari was well within his rights to approach the referee.
"Players should feel comfortable bringing any issue to the attention of the referee, especially one as significant as allegations of racism in the workplace."