Trainer Mark Newnham is planning to run dual Group One-winning three-year-old Shadow Hero in the Rosehill Guineas despite also nominating him for the weight-for-age Ranvet Stakes.

Shadow Hero has already taken out the first leg of the Sydney autumn triple crown for three-year-olds, the Group One Randwick Guineas (1600m).

Shadow Hero was the $3.50 favourite on Monday for Saturday's Group One Rosehill Guineas (2000m) for three-year-olds which is one of five Group One races on the Golden Slipper program at Rosehill.

"He'll run in the Guineas," Newnham said.

"I put him in the Ranvet just in case the Guineas ended up 16 runners and he came up with barrier 16 or something and the other ended up with five or six runners, but I'm 99 per cent sure I'll be running him in the Guineas."

After hitting the line well for fifth in the Hobartville Stakes (1400m) in the first start of his autumn campaign, Shadow Hero was an impressive winner of the Randwick Guineas (1600m) last start.

The win was his second Group One victory after he took out the Spring Champion Stakes (2000m) at Randwick in October.

Newnham said Shadow Hero had come through the Randwick Guineas probably better than any of his other wins.

"That's probably just a sign of maturity more than anything," he said.

"Looking at him this morning before he galloped and he was right back to his right weight and appearance.

"He did a bit of work this morning on the course proper at Warwick Farm and it was really good. Josh (Parr) was all smiles when he came back on him so it's all systems go for Saturday."

Newnham expected Shadow Hero to be a force to be reckoned with in anything he ran in this autumn once he got to 1600m in the Randwick Guineas, and the trainer expects him to be the one to beat again in the Rosehill Guineas.

"I thought he was the run of the race in the Hobartville Stakes first-up," he said.

"His sectionals were the best in the Hobartville and his sectionals were the best again in the Randwick Guineas so I think he's certainly the best of them," Newnham said.

"So with even luck I couldn't see him not in the first couple."