The soldier, who was on initial recruit training at the Singleton School of Infantry, received the serious injury in the fight that also left another three of his colleagues needing medical attention.

On Sunday afternoon an 18-year-old Singleton man was charged with assault, assault occasioning actual bodily harm in company of others and affray.

On Tuesday a second person was charged in relation to the incident.

The 18-year-old Singleton man was charged with assault occasioning actual bodily harm in company of others, affray and recklessly cause grevious bodily harm.

Both men are due to appear in Singleton Local Court on July 16.

Police are continuing their investigations into the incident and expect to lay more charges against other individuals involved.

Any witnesses that may not have come forward are asked to contact police at Singleton or Muswellbrook Police Stations to help with investigations.

Hunter New England Health confirmed the soldier, who was airlifted to the John Hunter Hospital on Friday night in a serious condition was discharged from hospital on Thursday morning.

He is now receiving ongoing treatment in his steps towards his recovery which is being managed by the Army.

The other soldiers involved in the fight are also on their way to making a good recovery.