Star New Zealand mare Bonneval has suffered a career-threatening injury to a suspensory ligament.

Andrew Forsman, the training partner of Murray Baker, said the New Zealand Horse of the Year was found to have swelling in a leg on Friday morning and scans confirmed the suspensory issue.

"There was some swelling around her fetlock joint this morning and a scan has confirmed a suspensory ligament issue," Forsman told NZ Racing Desk.

"Her CV is very good. She's achieved an awful lot, and another scan in 10 days' time will show the full extent of the injury and the prognosis going forward and whether we have another crack in the spring.

"She hasn't got anything left to prove so we'll just have to wait and see what the future holds."

Bonneval won the New Zealand Oaks and Australian Oaks as a three-year-old and returned in the spring to take out the Underwood Stakes in Melbourne.

The stable will still have an autumn carnival presence with Francaletta and Weather With You already in Sydney.

"They travelled well and Francaletta will run at Randwick on Saturday week, but we're not exactly sure which way Weather With You will go heading toward the Derby," Forsman said.

The winner of six of her nine starts, Francaletta will have her first Sydney start in the Group Two Guy Walter Stakes (1400m).