There is a new chapter in the Book of Feuds and it involves the Rabbitohs and Roosters women's teams.

The latest instalment in the game's oldest rivalry prompted the NRL to send a reminder to the four clubs in the inaugural NRL Holden Women's Premiership that teams in the Harvey Norman NSW Women's Premiership had first call on their players while they were still playing in the finals.

South Sydney will play Mounties in the NSW grand final at ANZ Stadium on Friday night and six of the Rabbitohs squad are contracted to Sydney Roosters for the upcoming NRL competition, which also features the Broncos, Dragons and Warriors.

The unusual situation is set to result in Roosters fans cheering for Souths in the grand final, while the Bondi-based club's NRL squad will watch the women play before their clash with the top-of-the-table Rabbitohs.

However, it has also caused concerns in the Rabbitohs camp over a potential conflict between training sessions and promotional activities that the players, headed by NSW State of Origin captain Maddie Studdon, are involved with for the Roosters.

The Roosters, who have also signed Mounties star Simaima Taufa, posted a video and photos on their website from the squad's first week of training, while the players were introduced to the crowd at last Saturday night's match against North Queensland at Allianz Stadium.

Souths are understood to have expressed concern about the training load on their players as they train each Monday, Tuesday and Thursday with the Rabbitohs and attended a session with the Roosters last Wednesday.

The Rabbitohs were also unhappy with the players undergoing fitness testing 24 hours before their 14-12 semi-final loss to Mounties on July 28, while it is alleged that one was advised not to play.

However, Roosters officials told that the session involved medical screening, as opposed to fitness testing, and said the players had only taken part in a light workout at training last week.

The NRL responded by advising the Roosters, Dragons, Broncos and Warriors that training was on a voluntary basis for players who still had commitments with teams in the NSW and Queensland women's competitions.  

Souths and the Roosters were among six clubs to apply for five-year licences in the NRL Women's Premiership but the NRL decided to start with a four-team competition, which will be played as double-headers with men's finals series matches.