Free Of Doubt's rating rose 10 points after his last-start win but the Jason Petch-trained galloper will carry less weight in his bid for back-to-back victories at Flemington.

Free Of Doubt won narrowly with 54.5kg at Flemington on July 19 but will carry half a kilogram less despite Racing Victoria's handicappers elevating his rating from 78 to 88.

Petch explained Craig Newitt rode Free Of Doubt a half-kilogram over his handicap at his last outing but every gram will count in Saturday's Jacinta Nugent & Lesley Millson Handicap (1400m).

The Mornington trainer said Free Of Doubt's size hampered his ability to carry big weights so he needed to keep him as low in the handicaps as possible, which would also produce a problem placing the five-year-old if he won the $80,000 race.

"He's only a small horse and he's not a great weight carrier so a race like tomorrow's down on the minimum really suits him," Petch said.

"He's by Not A Single Doubt, who is a little horse himself, and he puts that into a lot of his progeny so they struggle when they get up in the weights."

TAB Fixed Odds has eased Free Of Doubt's quote from $5 to $6 while the David Hayes and Tom Dabernig-trained Jacquinot Bay has firmed from $12 into $6 to be equal second favourite behind Eximius at $5.50.

Free Of Doubt defeated Loot `N' Run in his latest Flemington win and the pair meet again on the same weight terms but Petch says the front runner looms as one of his charge's major threats.

"There doesn't look to be a lot of speed in the race," Petch said.

"Loot `N' Run has drawn outside us and our bloke needs to fire away from the gates to get up there and be competitive."