John Sadler is hoping the owners of Lonrockstar are proven correct with their insistence the sprinter runs in a stakes race at Flemington.

Lonrockstar was scratched from the William Hill Handicap at Moonee Valley on Saturday to run in Sunday's Group Three Standish Handicap.

His trainer thought the Moonee Valley race suited Lonrockstar but it was the owners' wish for the seven-year-old to run at Flemington.

"I'd love to see them prove me wrong," Sadler said.

But Sadler sees a few negatives, the biggest one being the farcical situation where all horses are being asked to carry the same weight of 58kg.

It came about because the original topweight, Lucky Hussler, was not an acceptor for the race and as all other horses were weighted on 54kg the weights were raised 4kg.

Sadler was critical of the fact that being a Group Three race, weights could not altered but was happy to learn the situation was likely to be rectified next month.

Lonrockstar finished an unlucky seventh in last year's Standish when better off at the weights and Sadler said the gelding entered Sunday's race in good order.

And he said Lonrockstar's first-up seventh behind Decision Time over 1100m at Flemington on December 17 was a better effort than it appeared on paper.

Sadler's son Tom rode Lonrockstar on that occasion with Luke Nolen taking over on Sunday.

"Tom said he was in mid-air for around 100 metres in that race," Sadler said.

"He was in a position that day where everyone wanted to get to and they carried him along for a while.

"He didn't like that too much.

"When they went across the line my first reaction was one of disappointment but after looking at the video a few times I thought it wasn't too bad."

Lonrockstar is rated one of the outsiders at $21 with Divine Mr Artie the $2.60 favourite for Sunday's race.