David Partridge, Scott Brown, Bradley Orr and Steve Brooker were all charged with affray following an altercation in the early hours of October 12 last year.
Brooker, Orr and Partridge pleaded guilty to affray in a hearing at Bristol Crown Court on Friday.
Partridge, who has seven caps for Wals, also pleaded guilty to a charge of assault.
The four will be sentenced at a later date. No details of the incident were read in court, though two doormen were also charged with assault.