The former footballer said: "They were there again.
"I asked them what their problem was, but they just started calling me a w***er and things like that.
"I said I would take any of them on one-on-one outside, but they suddenly all piled on."
The footballer received hospital treatment after the attack at 3.30am yesterday, and is today recovering at his home in Cannock, Staffordshire.
Collymore has now made an official complaint to police in Ireland.
However, aspects of his account have been called into question by sources at the nightclub, who claimed he punched three players inside the club before following them to Burger King.