Ulster are to lodge a complaint with the organisers of the Heineken Cup following ugly scenes during their 28-13 defeat at Toulouse on Sunday.
Toulouse player Trevor Brennan clashed with Ulster fans
Coach Mark McCall said the Irish province would be citing Toulouse player Trevor Brennan for allegedly striking Ulster lock Justin Harrison.
Both players were sin-binned but McCall insisted Brennan should have been given a straight red card.
Brennan could be in further trouble for clashing with Ulster fans.
Ulster chief executive Mike Reid was expected to make a statement on Sunday night.
Coach McCall confirmed: "We will be lodging a complaint against Trevor Brennan for what he did to our player.
"We are very lucky Justin has not got something seriously wrong with him."
Ulster lost the match 28-13, although both sides were already out of contention for a quarter-final place.