Byrne was originally set to join Boston Utd, but pulled out after reports that his girlfriend was not happy about moving to Lincolnshire. The free agent spent some time at Swansea on loan last season, and featured in their tense FA Cup defeat at Tranmere.
Reports also suggest that Byrne has been joined on trial by another currently unknown player. The second trialist is also likely to feature in today's Hereford friendly.