Lizzie L'amour stunned co-trainer Murray Baker when she pulled up with a problem after her first-up flop but the Kiwi horseman has the mare primed for a sharp improvement at Moonee Valley on Friday night.
Lizzie L'amour was a Group I winner at her last New Zealand run in March but was beaten a long way from home when finishing more than 27 lengths from the winner at her Australian debut in the Group II Dato Tan Chin Nam Stakes on September 9.
Jockey Damien Oliver thought there was an issue with Lizzie L'amour before vets confirmed the five-year-old had pulled up with atrial fibrillation, which surprised Baker.
"I can't remember the last horse I've had that had it from a veterinary point of view where they have examined one," Baker, who trains Lizzie L'amour in partnership with Andrew Forsman, said.
"There was two in that race (with atrial fibrillation) and that's very unusual. There was no reason, it just happened."
Lizzie L'amour had to complete a jumpout at Flemington and pass an ECG test before she was cleared to resume racing but Baker said the five-year-old has worked well since her Valley run.
Lizzie L'amour will return to Moonee Valley to compete in mares' grade in the Group II Stocks Stakes (1600m) and Baker is confident of an improved showing.
"They say it doesn't occur again in 90 percent of cases but who knows?" Baker said.
"I've galloped her and worked her as normal. She's had no favours because she's a Zabeel and they are as tough as teeth.
"She has been perfect since."
Hugh Bowman, who won the Victoria Derby on Lion Tamer for Baker in 2010, will take over from the suspended Oliver aboard Lizzie L'amour at Moonee Valley.
Lizzie L'amour has firmed from $9 to $8 in Sportsbet's Stocks Stakes market in which Group I winner I Am A Star has shortened into $3.10 favouritism ahead of Hell Or Highwater, who has drifted from $3.50 to $4.50.