Pro14 organisers have confirmed they are in talks about increasing the number of South African teams in the competition.
League bosses also hope South African teams will still join the 2020-21 campaign in the new year.
Cheetahs and Southern Kings have been the two sides involved in the Pro14.
Kings will not be involved in 2020-21 after going into liquidation and negotiations are ongoing about which franchise will take their place.
A Pro14 statement said: "On August 25, Pro14 Rugby acknowledged under current international travel restrictions it is not possible for South African teams to fulfil Guinness Pro14 fixtures until 2021.
"Pro14 Rugby welcomes the news that the South African Rugby Union (SA Rugby) has been able to arrange a domestic schedule for its professional teams and that this is the first step in the return of their teams to on-field action.
"SA Rugby's long-standing commitments are to field two teams in the Guinness Pro14 and in light of the withdrawal of the Southern Kings, discussions are on-going about fulfilling this agreement from 2021 using a replacement team from its current professional franchises.
"Additionally, both Pro14 Rugby and SA Rugby are in early discussions about potentially expanding the tournament and deepening our partnership to include more South African franchises from 2021."
The league confirmed in August the South African sides will not play in the Pro14 for the rest of 2020, missing the start of the 2020-21 season, but Pro14 bosses are still negotiating with SA Rugby about involvement in this campaign.
The 12 teams from Wales, Ireland, Scotland and Italy will begin the new campaign with the first round of 11 fixtures not involving the South African sides.
In the longer term, and as a result of significant changes to rugby's global competition structures, the Pro14 is the likely future home for more South African involvement.
When the southern hemisphere's Super Rugby was cut from 18 to 14 teams in 2017, SA rugby's Kings and Cheetahs were the ones to lose out before being welcomed into the what became the Pro14 fold.
In recent months, New Zealand has set out plans for its own future path, which does not involve Bulls, Lions, Stormers and Sharks.
Top tiers in English and French rugby involve domestic promotion and relegation, leaving the Pro14 - a competition of franchises, regions and provinces - open to potential expansion.