The 31-year old made a brief appearance in court today when his defence solicitor, Kathleen More, lodged a not guilty plea.
The footballer is charged with assaulting Damian Holahan by striking him on the head to his injury on 3 February 2013 in Malones Irish Bar in Forrest Road, Edinburgh.
Fiscal Depute, Sarah Lumsden, said there were six civilian witnesses and one police witness. Ms More said she was prepared for trial and there were no defence witnesses.
Riordan, who was capped three times for Scotland, left Hibs for Celtic in 2006, but returned to the Edinburgh side in 2008. He left the club in 2011 and since then has had short spells with a Chinese side, St Johnstone, Bristol Rovers and Alloa Athletic.
The trial will be heard at Edinburgh’s Justice of the Peace Court in May.