Three of the seven runners presented by the Riccarton trainer are fresh up.
One of those - Pop Hit - and another - Shanzou - are new to Carston's establishment, which he took over from Lisa Latta at the start of August.
Roc de Mac (race 2) will be the first of his fresh runners to load into the barriers, and one of three Carston rides for Wingatui jockey Courtney Barnes.
The 4yr-old mare placed once last season from six attempts and has done well with time in the paddock.
''She's a nice mare and has benefited from a good spell,'' he said.
''She'll take massive benefit from that run [today] but I'm happy with her.''
Pop Hit (race 3) might not attract the casual punters' money after some adequate summer form in the North Island turned sour in the autumn.
Carston was happy to take on the half-sister to Missteeflying, and her win in a six-horse trial at Ashburton was good enough on a slow track.
''Her form is very average but her trial win was quite good and her work has been good,'' he said.
''I'm expecting her to run well but the form line worries me a wee bit.''
Why Wait (race 5) is also fresh-up, although the 7yr-old is no stranger to Carston, who has looked after him for most of his 50-start career.
''He normally takes a run or two to come to it, to be honest,'' he said.
''He'll take benefit from the run. He hasn't had a trial. He might run out of puff but as long as he runs well, I'll be happy.''
Shanzou is a new arrival to Carston's barn after showing some talent in the north.
The Zizou gelding won over 1200m at Te Rapa in September last year, and her most recent run was a fourth for Pukekohe trainer Richard Collett at Ruakaka on August 29.
''It had a bit of a reputation up north. He's done well since I've had him and I'll be guided by [the run] about where I go from here, but he's a nice horse.''
The dead track at Timaru today should suit Edensong in race 7 after she battled to sixth at Ashburton four weeks ago on a slow8 surface.
''Third-up tomorrow I'll be expecting a lot better run on a good track.''
Carston opted for Stonemason over Missteeflying in race 8, solely on the draws.
Stonemason will start in barrier 6 at worst, while Missteeflying will be no closer than barrier 14 if a full field lines up.
''[Stonemason] will be ridden positive tomorrow - we'll put him up on the speed. The mare, she's as honest as the day is long - she's got a terrible barrier so she'll have to go back and be ridden for luck.''
Meanwhile, the Welcome Stakes at Riccarton next month is the medium-term target for What Choux Want after her impressive win in 2yr-old company at Riccarton on Saturday.
''She'll run again on the 24th at Riccarton and then we'll decide after that,'' Carston said.
''I'm really happy with her. She's done everything right and she's a real natural, so let's hope she continues to improve.''
