Sparring won the feature sprint last year while Boss Lady Rocks was also successful two years ago.

Both gallopers are once again well in the market with Sparring ($5.50) and Boss Lady Rocks ($7) second and third favourites respectively.

The biggest query on Sparring is top-weight of 61kg while Boss Lady Rocks was handed the widest barrier in the field of 13 runners before the scratching of Real Gun and Hi Poppy.

Stubbs said he had a leaning towards Sparring if he was forced to pick the best hope of his two stablemates.

"It won't be an easy task at all to defend the stable's Flat Knacker crown," Stubbs said.

"Sparring has got plenty of weight to carry and Boss Lady Rocks has got a very wide barrier to overcome.

"So both my horses are there to be beaten.

"But if I was forced to pick my best hope in the race, I would lean towards Sparring.

"Boss Lady Rocks has actually got the best race form.

"But Sparring is race fit and racing very well and I was very happy with his last-start performance at Moonee Valley.

"So you would have to have a leaning towards Sparring because Boss Lady Rocks is tackling the race without a trial or a jumpout.

"I still think I've got her fit enough to win first-up but I really can't answer that until after the race."

Boss Lady Rocks has been off the scene since July last year and resumes from a 36-week spell.

As well as winning the Flat Knacker previously, the talented mare is also a previous metropolitan winner at Moonee Valley to highlight her undoubted class.

Stubbs said fitness wouldn't be an issue ahead of Friday's feature sprint.

"She has done plenty of work, so I'm not concerned about her fitness-wise," he said.

"I'm probably more concerned about her manners because she can be a bit funny when she gets behind the barriers at times.

"She wears a blindfold going to the barriers, so we won't tease her and leave that on her and go from there.

"She boasts a handy fresh record and won well at Moonee Valley first-up two preparations ago.

"So she is the sort of horse that is more than capable of producing her best first-up.

"If she can produce something like she did first-up at Moonee Valley, then I would expect her to be fighting out the finish in a race like the Flat Knacker."

Sparring is also flying this preparation after two wins at Wagga and Albury and two eye-catching fourths at Moonee Valley.

"Sparring hasn't put a foot wrong this preparation and I think last start at Moonee Valley was arguably the best run of his career," Stubbs said.

"I know he ran fourth but he stormed home late against a very good field and the time was superb.

"If he can reproduce that, you would have to give him a huge chance in this race.

"Physically he is a very solid horse and he is built to carry weight and I don't think that will worry him.

"He's drawn to get an economical run and should take up a forward position and you wouldn't think he will do as much work in the race as Boss Lady Rocks."

Sparring will be partnered by Tyler Schiller while Jason Lyon takes the mount on Boss Lady Rocks.