The new weight scale in Sydney has caused some headaches but has worked in favour of the Gary Portelli-trained Cosmic Cameo in the Summer Sprint at Warwick Farm.

While much of Portelli's focus on Saturday will be on two-year-old Single Bullet, he is happy to see Cosmic Cameo get his chance with the lightest weight the six-year-old has ever carried as he lines up for his 36th start.

Cosmic Cameo gets into the 1000m-race with 50kg after apprentice Deanne Panya's claim.

"The new weight scale is confusing because with the need for a 53 kilo minimum you don't know until acceptances what your horse might have," Portelli said.

"You might book a jockey like Hugh Bowman but when the acceptances are taken your horse doesn't get his weight and you have to look elsewhere.

"In this case with Cosmic Cameo Deanne was always booked and he's now on the minimum so with her three kilo claim he has 50 kilos.

"It works in some horses' favour.

"His last two wins have been at Warwick Farm so he has to be in this with a chance."

Cosmic Cameo was at $11 with the TAB on Friday while Single Bullet was the $1.70 favourite for the two-year-old race.

He is also high in markets for the Magic Millions Classic on Saturday week but his trainer has warned he is by no means a certain starter.

"To be assured of a start he has to win or come second on Saturday but even then we would have to see how he came through the race," Portelli said.

"I think he has a huge future going forward. I want to have a horse as a three-year-old and I don't want to sacrifice that future for one race.

"If he can win on Saturday that goes a long way to getting him into the Golden Slipper and I'm not sure he's the sort of horse who can back up a week later into a race like the Magic Millions.

"I'll see how he is on Sunday and Monday before finally deciding but it would be 50-50 at this stage."

Cosmic Cameo also holds an entry to the Magic Millions Sprint but Portelli will rely on last-start Bribie Handicap winner Straturbo in that race.