Success in the Inglis Nursery can provide a platform for Golden Slipper glory, but John O'Shea isn't sure it can do the same for Irish Bet.

The Smart Missile colt made the perfect start to his career when claiming the Inglis Nursery at Randwick in December, and after an eight-week let-up he steps out in Saturday's Pierro Plate (1100m) at the same track.

O'Shea, who is building his stable after splitting with Godolphin last April, accepts talented two-year-olds are automatically linked to next month's $3.5 million Golden Slipper.

The Inglis Nursery is developing into a reliable form reference for the major juvenile races over autumn with Mossfun (2014) and She Will Reign (2017) winning before claiming the world's richest race for two-year-olds.

"I think he could make the field, but he would have to improve quite a bit to be in the finish of a Slipper," O'Shea said.

"I've always told the bosses at China Horse Club that he's probably just a tier below those top-grade horses," O'Shea said.

Irish Bet can force O'Shea to reassess his opinion in the Pierro Plate.

"He's had a bit of a freshen up. He's had an easy trial and he's got good improvement from whatever he does on Saturday," O'Shea said.

"He's matured a little bit over the last two months. He's coping really well with his workload and he's probably more relaxed."