Jim Bolger, Aidan O'Brien and Paul Deegan will each fire twin assaults on Thursday's Japanese Racing Association Tyros Stakes at Leopardstown.
Deegan saddles both Roscommon scorer Henshaw and Limerick winner Spinamiss in a seven-furlong Group Three that counts Teofilo (2006), New Approach (2007), Rip Van Winkle (2008) and last year's victor Gleneagles among its previous winners.
Deegan said: "It would be difficult enough to split them. They're two nice horses.
"Henshaw is still a big, tall horse, who will be a better horse next season. It might come a bit soon for him and he might still be a bit green, but he's got plenty of ability.
"The filly has a beautiful pedigree and we think she's very decent.
"She's come forward from her second run and we're hoping for nice runs from the two of them.
"We think they're both up to this level, but it is a very hot race."
Aidan O'Brien and Jim Bolger have dominated the Tyros Stakes in recent years, saddling eight and nine winners of the race respectively.
O'Brien will be represented by Listowel winner Deauville and Lieutenant General, who is fitted with blinkers as he bids to open his account at the third attempt.
Sanus Per Aquam appears Bolger's main hope, having beaten Lieutenant General on debut at the Curragh before sauntering clear over this course and distance a fortnight ago.
The master of Coolcullen also saddles likely pacemaker Gleine.
The seven-strong field is completed by a British raider in the shape of Kevin Ryan's Taking Libertys, who has won each of his two starts to date.
