Players' union chairman Clarke Carlisle has repeated his call for Serbia to be banned from international competition if the charge of racist chanting against them is upheld.
European governing body UEFA hold their disciplinary hearing on Thursday after charging the Serbian football association (FSS) over the alleged racist chanting of fans during their Under-21 European Championship qualifier against England last month.
Professional Footballers' Association chairman Carlisle, speaking at the Street League Academy in Manchester, said: "What I saw was disgusting racial abuse from the crowd to the players. I saw physical altercations on the pitch that developed into a mass brawl."
The FSS and the Football Association are also facing further charges relating to the behaviour of their players at the end of the match in Krusevac.
Carlisle added: "I don't want to have biased eyes and say that the English team acted completely in self defence, but that's how it looked to me. I just hope that it was a thorough and genuine investigation."
When asked what appropriate punishment for that might be, Carlisle said: "The only way that you persuade a nation, or perpetrators to address the issue is to impose a sanction that has an impact.
"When we, as English teams, were kicked out of (European) competition, that instigated a period of self-governance. We started to crack down on physical violence, on hooliganism at football matches, so that we could get back into European competition."
Amid chaotic scenes at the end of the match on October 16, defender Danny Rose was sent off after the final whistle for kicking the ball away in reaction to the abuse he was receiving. He later claimed the abuse was racial. The FSS later blamed Rose and accused him of "inappropriate, unsportsmanlike and vulgar" behaviour.
UEFA's proceedings have been conducted independently from a separate investigation by Serbian police.
England players Steven Caulker and Tom Lees and coach Steve Wigley were among 11 people police submitted charges against over the scenes at the end of the game. The charges were being considered by the Serbian public prosecutor.