Shinn is a form rider, with three group wins in Sydney within the last 10 days. He partnered former New Zealand galloper Tavago to win the A$350,000 Sky High Stakes at Rosehill last Saturday and won the A$500,000 Challenge Stakes on English and the A$300,000 Todman Stakes on Gunnison the previous weekend.
He also won the group 3 Zeditave Stakes at Caulfield on February 25 and ran second in the group 1 Blue Diamond Stakes on leading Golden Slipper contender Pariah.
Shinn won the 2016 Golden Slipper on Capitalist but his career high point has been his Melbourne Cup win on Viewed in 2008.
Shinn, 29, will be riding at Ellerslie for the third time. He ran second on Hasahalo - who will be among Summer Passage's rivals on Thursday - in the Karaka Million in January and also rode at the 2016 Karaka Million meeting.
He has yet to win a race in New Zealand but has had four placings from his six rides and ran third on Tavago in the Karaka Mile last year and fourth on stablemate Caorunn in the 2016 Karaka Million.
Purton was unable to return to Auckland on Thursday because of Hong Kong commitments while Waddell, who had been engaged for five horses, including Kawi in the Group I Bonecrusher Stakes, has been thwarted by the change of date for Cup day.
Waddell had been due to start a suspension last Sunday, which will end on March 23.
He applied to the Judicial Control Authority (JCA) for permission to ride at Thursday's rescheduled meeting but his request was turned down yesterday.
A release from the JCA Board said that "the request cannot be met as the Rules of Racing do not provide for a review or a recall of a judicial committee's decision under the circumstances arising in this matter. The abandonment of a meeting invariably impacts jockeys, some arguably beneficially and others not so.
"The JCA Board also notes that Mr Waddell is not the only jockey impacted by the rescheduling of last Saturday's meeting and there are several others whose current period of suspension includes Thursday, March 16."
Waddell still has the option of appealing against the original decision to suspend him and is awaiting legal advice before he and manager Darryl Anderson make a decision. The deadline for an appeal is 4pm today.
Allan Sharrock, who trains Kawi, will delay making a decision on Kawi's rider till after Waddell has exhausted all his options.
The Auckland Cup market has been revised following the change of date and Chenille, who had lost favour with the prospect of a wet track, was back at the top of the market at $6 yesterday
