The season was scheduled to begin on October 3, however the return of regional Victoria to stage three restrictions until the early stages of September has thrown a major spanner in the works.
GMC chairman Jason Turner said a delay was highly likely.
“The likelihood of an October 3 start is now significantly low,” he said in a statement.
“As with many things right now, there is general uncertainty around what we can and can't do in the immediate future and even less for what we can do in the mid to long term future (in cricket season talk).”
Turner said will the organisation would not meet earlier than currently scheduled to allow time for information to be collected.
“We appreciate that all clubs have their own ideas on what should and shouldn't happen but please know that all options will be considered and what was provided in terms of playing dates and formats previously were done so in the hope that a full unaffected season may have been possible.
“It was looking good until the second wave hit but we all realise that it will almost definitely change.”
The statement said the competition would do what had to be done to get as complete a season played as possible.
“We are very lucky that cricket has great flexibility to play different formats of matches and this flexibility will need to be utilised for season 2020/21,” Turner said.
“Pleas respect those that have extreme difficulty task of making these decisions moving forward and delivering competitions and programs to the broader GMC cricketing community.
“It's a difficult time, we can only do what we can do, and we'll do the best we can with what we have and what is best for cricket in the GMC.”