Missrock has tuned up for the Newmarket Handicap with a hard-held narrow victory in a Cranbourne barrier trial.

The Robbie Laing-trained mare was under a stranglehold throughout Monday's 800m-trial, gaining a last stride victory under Ben Thompson.

Missrock ran 46.34 seconds for the trial, the fourth fastest of the 11 800m heats.

Laing said the trial was perfect ahead of Saturday's Group One race over the straight 1200 metres at Flemington.

"That was beautiful, just what the doctor ordered," Laing said.

"She settled fourth, strode through and I said to Ben if she runs third or fourth I'll be happy with that.

"She strolled to the line under a triple hold and beat them on the line.

"The time was good, she had an easy morning and pulled up a treat."

With the trial performance under her belt, Laing said Missrock would be kept ticking over during the week with a gallop at Cranbourne on Thursday morning to finish off her preparation.

At her most recent start, Missrock finished third behind Redkirk Warrior and Redzel in the Group One Lightning Stakes (1000m) at Flemington on February 17.

The mare has 52kg in the Newmarket and will be ridden by Tasmanian-based Craig Newitt.

Laing also saddles Lord Of The Sky in Saturday's race.

Lord Of The Sky, a brave fifth in the C F Orr Stakes on February 10, finished at the tail of the field at his most recent outing behind Brave Smash in the Futurity Stakes a fortnight later.

Missrock was a $17 chance with Lord Of The Sky at $41 after Tuesday's declaration of the final field.

Merchant Navy, winner of the Coolmore Stud Stakes over the same course and distance in the spring, is the $4.60 favourite.

But there has already been support for the two at the top of the weights, Redkirk Warrior and Brave Smash.

Redkirk Warrior is aiming to become the first horse since Razor Sharp (1982-83) to win back-to-back Newmarket Handicaps and has firmed from $9 to $7.50 while Futurity winner Brave Smash has firmed from $9 to $8.

Tony McEvoy was forced to abandon plans to start Hey Doc after the gelding failed to recover from pectoral muscle soreness and is instead aiming him at the William Reid Stakes at Moonee Valley on March 23.