The footballer adds matter-of-factly that racism is everywhere and getting worse, which perhaps explains why he's not unaccustomed to being abused for the color of his skin.
But on April 30, when the Ghana midfielder left the pitch during a top flight Italian league game after being booked for complaining of being abused by a section of fans, he said his "cup was full."
"I couldn't take it anymore," he tells CNN Sport in an emotional interview. "I'm human."
A week on and that top-flight match against Cagliari in Sardinia still feels like yesterday to the Pescara player.
He composes himself as the emotions of that day come flooding back. He remembers talking to the fans, pleading with the referee Daniele Minelli to stop the game, before walking off after receiving a yellow card.
"He (the referee) told me I shouldn't talk to the fans," said the former AC Milan midfielder.
"I can be abused and not say anything about it -- that's when I got angry. I told him this is about my skin color.
"I don't know where I got my patience from, because I was really cool and then I just walked off the pitch."
'This isn't the first time'
Muntari initially received a one-match ban for the two yellow cards he received in that match -- the first for dissent and the second for leaving the pitch.
The suspension was later rescinded, but the former Ghana international says he was "treated like a criminal."
If the treatment of Muntari has received worldwide attention, it seems to have had little effect on some fans who attend Serie A games.
Muntari was on the substitutes' bench for his club's home game against Crotone in the Stadio Adriatico Sunday and said he could hear a player being abused.
Asked how often incidents of racism happened in football, Muntari told CNN Sport: "Every game. I was sitting down [Sunday] and it was happening. There was a player playing and it was happening in the stands so how are we going to tackle this?
"This isn't the first time it has happened. We talk about it and after maybe one week, two weeks it's gone. Then, maybe after a month or two later, it happens somewhere and you get calls to talk about it and then it's shut again."
The footballer said he would be the "No.1" supporter of any organized player boycott in protest against racism.
He also said the political and economic climate in Europe had played a part in what he believed were increasing incidents of racism in the sport.
"Maybe sometimes it's frustration, there's no work, there's no job," he said. "Countries are taking a lot of people they aren't used to. Things are changing, and maybe that's part of it."
Leading anti-racism campaigner Piara Powar told CNN Sport that player boycotts were credible, before adding that footballers in Italy needed to be "more active."
"In a country like Italy, where there are big name players who feel very strongly about these issues, then a boycott is one way to go," said Powar, executive director of Football Against Racism in Europe (FARE).
"In the end, it's the way the boycott is received, the way in which the Italian FA changes the way it looks at these issues, the education of the fans. More needs to be done on all of those.
"[Boycotts] are a very good way of taking this forward. We've seen it in the US, don't forget, on issues around race there. Why not in Italy?"
In overturning Muntari's initial suspension for his two yellow cards against Cagliari, the Italian Football Federation (FIGC) said it had considered the "particular delicacy" of the case.
The FIGC told CNN it had no comment to make regarding Muntari's claims that racism in football had become worse during the course of his career.
The organization that runs top-flight football in Italy -- Lega Serie A -- was not immediately available for comment.
Premier League an example
Muntari, who played in the English Premier League for Portsmouth between 2007 and 2008 and on loan for Sunderland in 2011, said Italian football should follow the lead of England's top flight.
In 1993, a year after the birth of the Premier League, the Football Association founded the anti-intolerance campaign 'Let's Kick Racism Out of Football' which, four years later, became the Kick It Out campaign.
"I'm not condemning Italy, but look at England, look at how English football is," said Muntari.
"It is totally different. It is amazing. I played there and never had any chat like that.
"Italian football is one of the best in the world. We have amazing players here, we have an amazing league and this shouldn't happen in Italian football."
Muntari not the first
Muntari is not the first footballer to suffer racist abuse in Italy's top division.
In 2013, Muntari's former AC Milan teammate Kevin-Prince Boateng walked off the pitch in protest during a friendly against Pro Patria. Muntari also played in that game.
Boateng replied in support of a tweet which Muntari posted at the weekend, which read: "I am determined to fight #racism. Football should inspire respect for one race -- the human race."
There have been other racist incidents involving soccer players across Europe during 2017.
In France's Ligue 1, some Bastia supporters directed monkey chants towards Nice striker Mario Balotelli.
Bastia received a suspended one-point deduction and was forced to close part of its stadium for three games.
And in April, a Glasgow Rangers supporter appeared in court after being identified as the fan who made a monkey gesture at Celtic forward Scott Sinclair after the player had scored in a Scottish Premier League match between the two rivals.