"I have been popping him over the odd hurdle in training to keep his mind on the job," Sharrock told the Herald.
"It freshens them up mentally and he loves it. He is fearless and just flies at them. I only started it a few weeks ago and it is really helping."
"I couldn't be happier with him now and I think he gets his best chance to beat the mare - but we all know how good she is."
Sharrock hopes the speed in the race out wide allows Tavi Mac to follow a horse like Supreme Heights across and then sit in the first five, near Avantage who has drawn barrier four.
"I think he is a better horse for the top-level racing he had last season and if you had reversed the runs they had in this race last season I reckon we would have gone close to beating her.
"So maybe we get our chance this week, if the meeting goes ahead."
Avantage hasn't started a race this campaign but she has had two trials, both of them solid without being pushed out. But that doesn't tell the whole story.
Avantage and some stablemates headed to Taupo for private trackwork just a few hours before the latest Covid outbreak last week and champion jockey Opie Bosson liked what he felt.
"She worked really well and it felt like she had come on after her trials," said Bosson.
"Jamie [Richards, trainer] asked me after her second trial whether she would need another and I thought a good track gallop would do it and that is how it felt to me last week.
"The only one I am worried about this week is Tavi Mac and he might enjoy a really wet track more than us but on class she should be too good for most of them."
While Bosson would usually struggle so early in the season to ride at Avantage's 57.5kgs tomorrow a stomach flu contracted late last week has been an unwelcome aid.
"Max [son] got it at kindy early last week I think so a few days later I got it, but it definitely helps the weight," joked Bosson.
That 57.5kgs is also the same weight he will ride the unbeaten Palamos at in the $80,000 Breeders Stakes earlier in the programme and while he is looking forward to getting back on the colt he does have a warning for punters.
"He was my top two-year-old ride all last season and I really rate him.
"But I have also ridden Imperatriz in work and she is flying. They are both very good and it might come down to luck but it is going to be hard to give her weight and beat her."