All the rage Saturday racing-wise is on Winx in Sydney this afternoon, but over in Perth the 2017 WATC Derby betting markets have been shaken-up with the scratching of the favourite Royal Star.

The gun Grant & Alana Williams-trained filly was the well-supported top fancy in markets at Ladbrokes.com.au for this afternoon’s $400,000 Group 2 Schweppes W.A.T.C. Derby (2400m) at Ascot Racecourse.

The daughter of Redoute’s Choice, last seen running a narrow second as the beaten odds-on favourite in the Group 3 WA Oaks (2400m) a week ago, was pulled from the WATC Derby field on Friday afternoon due to joint issues.

Royal Star pulled up sore after a Friday morning gallop during which she struck a joint, forcing prolific Perth owner-breeder Bob Peters to scratch her from Saturday’s lucrative feature.

There looked to be no permanent damage in a subsequent scan, but Peters said they would undergo further tests once swelling subsided.

“So far the tendon and suspensory seems fine, but sometimes you have to wait until the swelling goes down,” Peters told The West Australian.

“We don’t really know what it is. We’ll probably get it re-scanned in a week or a couple of weeks.”

Updated WATC Derby odds at Ladbrokes.com.au now have the fellow Peters-raced filly Very Tempting as the firming $3.20 favourite (in from $4.40).

Also prepared by Team Williams who have won the past two editions of the race with fillies Delicacy (2015) and Arcadia Dream (2016) beating home the colts and geldings, Very Tempting comes off the WA Oaks win at the track and distance last Saturday.

She jumps from a wide barrier 12 of 15 draw with Chris Parnham to ride and is followed in the latest WATC Derby betting markets by Gatting ($4.80).

Darren McAuliffe prepares the in-form son of Hard Spun who comes off a win in another traditional Western Australian Derby lead-up, the Listed Melvista Stakes (2200m) back on March 25.

Another top hope to hold out the filly this afternoon in the WATC Derby results out of the Melvista Stakes is the third-placed Taxagano with the outside alley to overcome.

The Stan Bates-trained Rogano gelding made up all the ground as a $51 roughie last time out coming from near last to within three-quarters of a length of the winner Gatting in his first run over further than 1800m.

Owner Rod Lukatelich remains hopeful of a WATC Derby win this autumn with Taxagano, a $9 chance in the latest markets, but admits the barrier was a blow.

“We would have liked a slightly better draw, but with some luck he’ll be in the thick of it,” Lukatelich said.

“I thought he produced the best staying performance in the Melvista. When he stretches out he has an enormous stride.”

The Melvista Stakes runner-up Final Salute had better luck barrier-wise for the Group 2 rematch, Peter Hall replacing William Pike – who was to ride Royal Star – in the saddle of the Not A Single Doubt gelding in gate six.

Final Salute won the Listed J.C. Robert Stakes (1800m) the start before and has claims to turn the tables on Gatting this afternoon.

The other single-figure fancy is Victorian visitor Rock With You ($7.50) prepared by Leon & Troy Corstens who comes off a maiden win at Benalla over 2046m a fortnight ago by a barnstorming 13 lengths.

Check out the full WATC Derby 2017 betting odds now at Ladbrokes.com.au and back your Perth racing selections at the best autumn prices.