Spratt has the mount on Cong'er, whom she rode to a last-start win in the listed Karaka Classic (1600m) at Pukekohe on September 21.
The Matamata Cup is over the same distance.
Spratt won the Matamata Cup in 2010 on Atom Cat and last year on No Excuse Maggie.
Atom Cat is a rival tomorrow with Andrew Calder the rider.
Atom Cat has 57.5kg, 2kg more than he carried in 2010. Atom Cat ran sixth last year.
Karen Zimmerman, the Otaki trainer, who has won the Matamata Cup with Rodin (2002), King Of Ashford (2006) and Bonjour (2007), has Amberio in the field. She has been runner-up in four of her five starts since a win over 1400m at Otaki.
No Excuse Maggie is in the $80,000Taranaki Breeders'Stakes tomorrow, with David Walsh the rider. The track at Hawera was dead yesterday but rain is forecast, which would suit No Excuse Maggie.
Guessing, who finished second to Dating in the Breeders' Stakes last year, is high on the list of fancies after seconds at her last two starts. Lisa Allpress has the mount on Floria, with Leith Innes under suspension. The Stephen McKee-trained Floria ran on late for fourth fresh up behind Antonio Lombardo at Ruakaka. Kekova, who was ridden by Allpress when a fast-finishing second to Ginner Hart at Hastings last month, has Hayden Tinsley in the saddle.
