Mick Bell believes Group One success is within touching distance for Jungle Edge, a horse he originally thought was city midweek grade at best.

The seven-year-old has made a mockery of that assessment ahead of The Galaxy (1100m) on Saturday at Rosehill, where a second placing will propel his career prize money past $1 million.

Cranbourne-based trainer Bell has his sights set higher for Jungle Edge as he tackles a Group One field for the seventh time.

Jungle Edge's impressive comeback when runner-up to Redzel in the Group Two Challenge Stakes (1000m), and favourable wet weather suggest he could improve on his previous best in elite company, a second to Clearly Innocent in last year's Kingsford Smith Cup at Eagle Farm.

"It's all come together so well it's unbelievable," Bell said.

"He's going very well, we think he's a better horse than last year and there's the weather too."

Jungle Edge's 13 wins have been achieved on soft or heavy tracks and with Rosehill unlikely to be upgraded to good for race day, Bell is confident.

"I feel he's just reaching his peak now," he said.

"He's no spring chicken, but he never started racing until he was close to five and over the last 18 months he's just got better and better."

Bell took over training Jungle Edge from part-owner Chris Strickland in early 2016 and was amazed at how he developed.

"I didn't think he was this good. When I wanted to get him I thought he was capable of winning a midweek race in town.

"It's all coming together like you wouldn't believe it but it's a Group One race, they don't give them away."

Jungle Edge was the $4.20 second elect with the TAB on Thursday behind In Her Time ($4), who opens her autumn campaign for Newcastle trainer Ben Smith.

"She goes well but she's got to run against a dead-set weight for age horse that is not badly off on the weight scale," Bell said.

He described Jungle Edge's run in the Challenge Stakes as "exceptional" after he hit the line 1-3/4 lengths behind Redzel.

"He struck the best sprinter in the world and matched up well against him," Bell said.

Pariah, Secret Agenda and Thronum have been scratched to run in the Group One William Reid Stakes (1200m) at Moonee Valley on Friday night.

The emergency, the Paul Perry-trained The Mission, now gets the chance for a first win since he claimed last year's Group One Champagne Stakes on a heavy track.