Carston took the Jimmy Choux filly north during the summer, where she performed with merit.
A third at her first look at Ellerslie in early January was followed up by a brave fifth in the Karaka Million and a smart third in the group 2 Matamata Breeders' Stakes in February.
Some trainers might have then looked at the Diamond Stakes at Ellerslie in March and the Manawatu Sires' Produce Stakes at Awapuni in April, but Carston decided against it.
"I purposely didn't go to the group 1 races, with this race as an aim,'' Carston said.
"I just felt she couldn't win the group 1s, so I didn't want to run eighth - I'd rather focus on a race which she'd be competitive in. She hasn't won a listed race, so it would be good to get that, but you never know.''
The 2yr-old had three weeks off at Kamada Park in Palmerston North before returning to Carston's Riccarton stables.
She has drawn the outside barrier in the 12-horse field, but the long 1200m chute at Riccarton does mitigate that awkward draw slightly.
"It's not as bad as it looks on paper,'' Carston said.
"Obviously, it's not ideal, but there's no point losing any sleep over something we have no control over.
"On form, she's the best horse in the race, but she's going to have to be from out there.''
The fine autumn conditions means the track was rated dead4 yesterday afternoon.
Carston said his filly should be able to cope with the firmer surface, especially as this was her last run before returning as a 3yr-old next season.
"The track is going to be pretty firm, which is not ideal for any of the 2yr-olds, but I was happy enough,'' he said.
"She's only going to have one run and she'll be back to the paddock after this race. The more I do with her, the more I think she'll get further than the 1200m. She'll obviously be aimed at the Canterbury Belle Stakes and then heading towards the [New Zealand] 1000 Guineas.''
Carston also has Strowan in the Champagne Stakes. He said his second on debut from a good barrier on April 2 was a better guide than his eighth from barrier 13 two weeks ago.
"He drew a bad gate, and he was off the track the trip and only got tired in the last bit. I thought his run was good enough to warrant going to this race. He'll be in it for a fair way . . . he's probably a place chance.''
Carston has four starters - Carmen Sandiego, Lincoln's Legacy, Pinzano and Steadfast - in the rating 65 1200m, although three of those are having their first start for him.
"Steadfast probably has the best form of the ex-North Islanders, but he's drawn 18. It's a watch-and-see with those southern debut runners.''
Montrachet (race 2) is the best of Carston's other runners on the day.
"She's a handy mare going places.''
