Physically he's a rising seven-year-old but mentally Planet Purple isn't quite there yet.

His immaturity is one of the reasons trainer Kerry Parker has opted to keep him close to home this weekend to race at Rosehill rather than take him to Brisbane for the Queensland Cup.

Although the $150,000 prize money at Eagle Farm is tempting and Parker has no concerns about the 3200 metres of the Eagle Farm feature, he is keen to keep Planet Purple in his comfort zone now that he has hit form.

Planet Purple will go to the 2400m Benchmark 80 seeking a hat-trick after breaking a two-year drought on June 10 and backing it up 12 days later with another tough win.

"He's not the most sensible horse in the world and not the best traveller so we have decided to stay in Sydney," Parker said.

"I think the race in Brisbane was a winnable race for him but after the trip there I'm not sure what would have walked off the float.

"He'll be meeting much the same field at Rosehill as last time so it's in his best interests to stay here."

Parker trains at Kembla Grange on the NSW south coast which has been hit particularly hard by the recent wet weather.

It has affected the preparations of some horses but not Planet Purple.

"He is a lean, fit racehorse and after he won over 2600 (metres) on a heavy 10 I wasn't going to do too much with him anyway," Parker said.

"He isn't the sort of horse that needs too much work. He doesn't carry any excess weight which is why we call him `Sticks' at home.

"He'll go to the race fit and well."

By staying in Sydney, Planet Purple also has the benefit of Kerrin McEvoy, an internationally regarded rider of stayers.

Secessio, who was a controversial second to Planet Purple at Randwick last Saturday week, is topweight for the race with 61kg while Planet Purple will carry 5kg less.

Apprentice Alysha Collett was suspended for her ride on Secessio. She failed in an appeal on Tuesday and will miss the next two Saturdays of racing.