Hippopus will back up in Saturday's Grand Prix Stakes as trainer Gai Waterhouse attempts to revive his flagging Queensland Derby campaign.

Hippopus beat only one rival home when he finished 12th in last Saturday's Group One Doomben Cup (2000m) won by imported stayer Beaten Up.

"Gai didn't really want him to go three weeks between runs into the Derby and he's pulled up well so the back-up isn't a problem," stable foreman Mark Newnham said.

"It's a good stepping stone to the Queensland Derby and it would be a nice race to win along the way."

Newnham says the son of High Chaparral will appreciate competing against his own age group at Doomben.

"His inexperience probably found him out in the Doomben Cup," he said.

"It's a fair drop back in grade to three-year-old Group Three level from Group One weight-for-age company."

Newnham said Hippopus had only just settled into a rhythm in the Doomben Cup when Manighar made an early bid for victory approaching the home turn.

"On face value he might've looked a little disappointing but he was out of his comfort zone against the older horses," he said.

"The step up to 2200 metres in the Grand Prix will suit him and although he's drawn a little awkwardly he'll roll forward and make his own luck."

Also backing up in the Grand Prix is VRC Oaks winner Dear Demi after her narrow win in The Roses at Doomben last Saturday.

Dear Demi drew barrier 17 in the Grand Prix but started from stall 16 when she won The Roses over 2000 metres and survived a protest from runner-up Gondokoro.