A refreshed Crown Witness puts her unbeaten run on the line when she returns from a short break in the $350,000 Blue Sapphire Stakes at Caulfield.

Crown Witness put together three-straight wins during July and August before being sent for a freshen-up after beating Catchy in the Group Three Quezette Stakes (1100m).

The filly has had a jump-out at Caulfield and also showed she was on target for Wednesday's Group Three Blue Sapphire (1200m) with a 3-1/2 length barrier trial win at Cranbourne last week.

Trainer Stuart Webb decided after the Quezette to bypass the Thousand Guineas, preferring to keep the talented filly to sprints.

"She was probably a bit sharp for the Guineas at this stage and I would have had to get too much work into her which she wouldn't have coped with," Webb said.

"She had had three solid runs, so she had a good little break.

"She had three weeks at the water walker and then did enough work into a medium trial at Caulfield and then she had a good trial at Cranbourne last week.

"I couldn't have been happier with her trial (at Cranbourne).

"She and Jukebox were the two good trials of the day."

Jukebox won his trial at Cranbourne by 4-1/2 lengths in slightly quicker time than Crown Witness and has been well-supported in early betting for the Blue Sapphire, firming from $5.50 to $3.80 favouritism with TAB fixed odds.

Jukebox won his first three races before finishing second to Catchy in the Group Two Danehill Stakes at Flemington last month at his most recent start.

The colt will be having his first start for trainer Aaron Purcell who has taken over Ciaron Maher's team of horses while Maher serves a six-month suspension.

Formality, from the Lindsay Park stable, is at $4.20 with Crown Witness at $4.60 in the field of 10 three-year-olds.

"Crown Witness beat Catchy and then Catchy went and beat Jukebox," Webb said.

"I'd say she, Jukebox and Formality are the three class horses of the race."

Crown Witness's performance will determine whether she presses on to the Group One Coolmore Stud Stakes (1200m) at Flemington next month.

"She would want to be running really well to warrant that," Webb said.