Group Nine will unveil a new draw for 2018 but Tumbarumba’s departure will not see a home and away season introduced.
The Greens made the shock move last week when they announced their intention to enter the Murray League.
It leaves 10 clubs in Group Nine, negating the need for a bye each week, but ground availability in Wagga will see some clubs host others twice this season.
Group Nine president Jack Morton confirmed the 18-round season would remain which each club to play each other twice.
“We can’t do home and away as there are no games in Wagga for the first two weeks,” Morton said.
“Clubs have to play away so home and away just doesn’t work.”
Morton is supportive of Tumbarumba’s decision.
“They have to do what is best for their town and as far as the Group goes we are 100 per cent behind them,” he said.
“It is a big decision for them but they have to do what is best for rugby league up there. I think they have, as they have been proactive and realise they are up against it.”
Morton also left the door open for the Greens to return to Group Nine in the future.
“We will not shut the door to them,” he said.
Tumbarumba have a cooling off period on their decision until January 29.
A new draw is expected to be officially released when the cooling off period ends, but the key dates for the season will not change.
The season will start on April 7 and culminates with the grand final on September 8.