Winx's Turnbull Stakes defence will be the second and probably last time the great mare will compete at the famous Flemington racetrack.

The champion won last year's Turnbull by 6-1/2-lengths and her trainer Chris Waller says Winx is "picture perfect" ahead of her bid to make it 28 successive victories and 21 Group One wins in Saturday's edition of the 2000m race.

The Turnbull is three weeks before Winx's main spring target, her bid for an unprecedented fourth Cox Plate at Moonee Valley.

Saturday will only be the sixth time the seven-year-old has raced in Melbourne and while no decision has been made on how much longer Winx's career will continue, Waller admits it is likely to be the final time she races at Flemington.

"I would say so," Waller said.

"We're just taking the one run at a time. We haven't got too far ahead of ourselves from that regard.

"Flemington on Saturday in the Turnbull Stakes is an important race and who knows what's around the corner with Winx.

"Who would have thought after one Cox Plate that we would have been here still now, and not just running but running with distinction.

"We do respect the horse. We do respect her age and we do respect that she won't be there forever but we're making the most of it and looking after her as best we can."

Waller says he is overwhelmed by the following Winx has earned, not just from racing fans but the general public.

"I also respect that the fans need to be told everything and they do want to know when she's going to stop racing. Well, we haven't said anything yet because she's not stopping yet," Waller said.

"So we just push on and take one day as it comes."

Waller said Winx was in perfect condition mentally and physically ahead of the Turnbull and ready to run to her best again.

"She hasn't got the world's best rating for nothing but we just need to make sure that she stays the same and she'll hold that rating," Waller said.

"So it will take a champion to beat her, or a day where she's no longer as dominant as she has been. But there's certainly been no signs of that.

"Luck in running is always a big part and we have respect for other runners and other jockeys, so we'll go into the race preparing that way and hopefully she does the rest."

Hugh Bowman, who rode the mare in a gallop at Flemington on Thursday, believes Winx is stronger physically and mentally this preparation.

"I'd be very reluctant to say she's better, because how could she be any better," he said.

"But she's certainly stronger."