The Fijian side relocated to Australia six months ago to compete in the Ron Massey Cup, after last year's competition was cancelled because of Covid-19.
The Silktails managed six wins, six losses and one draw in 13 matches before the competition was suspended at the start of July, with their last hitout a 26-16 win over Blacktown Workers on 24 June.
On Tuesday the New South Wales Rugby League Bord confirmed it had made the "very difficult decision to abandon a number of Major Competitions for the 2021 season" after the State Government last month extended the lockdown for the Greater Sydney Region.
The competitions affected include the New South Wales Cup, Women's Premiership, Jersey Flegg Cup, Sydney Shield and the Ron Massey Cup.
"With the current Public Health Order in force until at least 28 August, and there understandably being no current NSW Government sanctioned roadmap out of the lockdown for sport, the Board was left with little option but to cancel our Major Competitions," NSWRL Chief Executive David Trodden said.
"In reaching their decision, the Board considered its obligation to provide participants with a safe environment to play sport. The NSW Government's health advice, particularly the state of infection rates and vaccination rates, made it difficult to provide that environment in the immediate future.
"The NSWRL thanks our participants, officials and volunteers for their contribution to our Major Competitions this season. We urge them to remain safe, adhere to the COVID-19 safe guidelines and we look forward to their return in 2022."