Mike Cattell had no idea what he was setting in motion when he tossed in a late nomination for maiden galloper Royal Popcorn to run in the Group Three San Domenico Stakes.

The presence of the Nowra-trained gelding in the elite Rosehill field has prompted plenty of reaction, some believing the $151 shot is not good enough to be there, others delighted to see a battler from the bush taking a chance.

Racing NSW chief steward Marc Van Gestel even called Cattell to query his motives, while some Twitter followers have rallied behind the horse with the tagline #prayforpopcorn.

"It wasn't the intention to cause such a chaotic week," Cattell said.

"The owners come first, after the horse, and they've had a ball.

"There's 12 of them and I've been looking at their 'Whats App' messages and I think they'll provide a boost to the economy because they've all been out buying suits and dresses and hats."

The idea to run Royal Popcorn, who has been beaten by a total of almost 70 lengths in five unplaced starts, came to Cattell as he was driving home from trackwork on Tuesday.

As he was bemoaning the current drought conditions and wishing he could find a wet track for his horse, he heard on the radio that nominations had been extended for Saturday's San Domenico Stakes (1100m).

He had also heard rain was coming, so he checked the weather forecast for Sydney and finding it favourable, put his horse in the race.

Cattell had been pre-training and spelling horses for the likes of James Cummings and John Thompson for eight years before he took out his training licence a year ago.

He knows Royal Popcorn is not in the league of regally bred colts and rivals the ilk of Bivouac and Exceedance, but he also believes anything is possible if the Rosehill track is bottomless.

"He's not up to those expensive colts in class but wet tracks are very different to dry tracks," Cattell said.

"The jump-outs he's had on heavy tracks, they haven't seen which way he's gone."

With the scratchings of Dubious and Yes Yes Yes, the worst case scenario for Royal Popcorn in the small field is fifth place and a cheque for $5000.

Cattell hopes the horse can go even better and says his instructions to jockey Kathy O'Hara will be simple.

"The instructions will be to fire him out of the gates, go to the front and keep going for as long as you can," he said.

And then #prayforpopcorn.