Rome police announced the news on its website on Thursday.
Francesco Ianari and Mauro Pinnelli remain in jail after having initial charges of attempted homicide downgraded to aggravated wounding on Monday.
Seven people were injured in the attack, one with a knife, before Tottenham's Europa League match against Lazio.
The stabbing victim, Ashley Mills, remains in hospital after his femoral artery in his right thigh was gashed.
Police said about 50 hooligans, their faces covered by motorcycle helmets and scarves, stormed "The Drunken Ship" pub in Rome's Campo de' Fiori square where the Tottenham fans were drinking.