Balta was at the match in Altona North coaching the Croatian side before fans stormed the field and began fighting.
According to a report from The Herald Sun, Balta sustained minor bruising to his face after being struck in the unprovoked altercation, with Richmond understood to be investigating the matter.
It is believed Balta is an innocent victim of the incident, where fans ran onto the field and began fighting.
The Tigers' medical crew assessed Balta on Monday, with the 23-year-old expected to be back training as early as Tuesday.
Nations Footy Cup organisers released a statement following the incident.
“As organisers, a lot of effort goes into running this event,” the statement read.
“We were disappointed with the behaviour of some of the players and spectators.
“Nations Footy Cup is about inclusivity, diversity and unity bringing people of all backgrounds, beliefs and cultures together to unite over football.
“There were some incidents that took place yesterday that left a bitter taste.
“To our players, spectators and fans that had their experience negatively impacted by this, we apologise.
“At NFC we don't tolerate this behaviour.”
A member of Richmond's 2020 premiership side, Balta has played 62 games in the yellow and black since his debut in 2018.