Petite's Reward is the smallest horse in Brendan McCarthy's stable.

But she doesn't act like it.

"She's very tiny but she makes up for it with massive determination," McCarthy said.

"And she's actually the pushiest horse in the stable. She would walk right over the top of you. She has got this attitude where she doesn't like being told what to do. She likes doing it her way.

"She thinks she's 16 hands high. But she's not."

The free-running mare has been back in work for some time with McCarthy plotting a first-up tilt at Saturday's Zouki Handicap (1000m) at Moonee Valley where Petite's Reward has registered three of her five career wins.

McCarthy said given the mare's size it was hard to find the right races for her where she gets in with a decent weight.

But he said the 54.5kg, after the 1.5kg claim of premiership-chasing apprentice Beau Mertens, would be a key to her chances on Saturday as she aims for her first win since the corresponding meeting a year ago.

"She has got a pretty good overall record at the Valley and with her pattern of racing, that's what suits her to racing there," the Caulfield trainer said.

"She gets there and runs along and she does appreciate the short straight.

"This has been my target for her for quite a while.

"She has had four jump-outs to make sure she is cherry ripe going into this and gets every chance."

But the trainer also acknowledges the benchmark-84 race for mares is not an easy assignment with a number of noted speedsters engaged.

Petite's Reward is at $12 with Miss Vista the $3.80 favourite.

"There is a lot of speed in the race as well and it makes it a little bit difficult in the fact we've got a pretty wide gate," McCarthy said.

"There's a lot of speed drawn inside her as well as Miss Vista outside her.

"But I'm confident she will run well. She does race very well fresh and with the number of jump-outs she has had, she's going in pretty wound up and ready to go."