A third Celtic fan is in hospital after being stabbed in Rome following Thursday night’s match against Lazio.
The condition of the man, who is understood to be 20 years old, is not known.
Several Celtic supporters were also attacked when a shuttle bus transporting them from the stadium broke down and was ambushed.
It is not thought that any of these fans sustained serious injuries after their side’s 2-1 Europa League victory.
In the lead up to the game, two Celtic fans were stabbed by masked men outside the Flann O’Brien pub in the city.
Both were stabbed in the leg but their injuries are not life-threatening.
One of the men, aged 52, is still in hospital but the other has been released. Police said an investigation was ongoing.
Tensions were high after warnings that Lazio fans wanted revenge for a controversial banner unfurled by Celtic fans at a match in Glasgow last month.
The banner showed the Italian dictator Benito Mussolini hanging upside down.