"It is very disappointing but we don't think she is finished yet," Green said. "She was supposed to head to Menangle last week and then race in the Len Smith Mile next week but when she got back from Victoria she wasn't right.
"So she now has to spend three months out of work, most of it in a box, and then Bunty [trainer Brian Hughes] can start again.
"That means missing the Aussie winter features and the New Zealand Cup so the most likely first target is a race like the Queen Of Hearts [in December].
"But if she is not ready for that we will wait until she is ready, which could mean going back to Australia next season.
"Ideally though, we want her to be a racehorse again if she can. She has plenty of time to be a broodmare in the future.
"But if the injury doesn't heal as we want it to then that broodmare career might come earlier than we want."
The Orange Agent has won 23 of her 33 starts, placing in six others and won $746,423, setting five New Zealand records.
On top of this season's group ones she has also won a Harness Jewels in a record 1:51.1, the Northern Oaks by five lengths, the Nevele R Fillies Final and the Australasian Breeders Crown. She would have been a certainty for Mare of the Year at the HRNZ annual awards to be held on August 3 but for the Auckland Cup win of fellow superstar mare Dream About Me in December.