Tim Clark will be the new jockey for King's Troop when he has his last start before a spell at Rosehill.

With Brenton Avdulla, who has ridden the colt at both starts to date, heading to the US to ride at the Arlington Millions meeting in Chicago, Clark has been given the call-up in the Group Three San Domenico Stakes (1100m) on Saturday.

Avdulla will ride Goldstream for Australian Bloodstock in the Secretariat Stakes at Arlington on Saturday, the same race Adelaide won last year enroute to victory in the Cox Plate at Moonee Valley.

King's Troop will head for a spell after Saturday's race to do a bit more growing and maturing before the autumn.

The son of Redoute's Choice is also among nominations for the Vain Stakes (1100m) at Caulfield but trainer Gerald Ryan has elected to keep the colt on his home track at Rosehill.

"We'll keep him at home and then tip him out," Ryan said.

"It's his home track and I think horses always race better on their home track and I think it's a better choice than going to Melbourne."

A debut second to Japonisme on a heavy nine at Rosehill on July 18, King's Troop headed to Warwick Farm on August 5 recording a near four-length victory in maiden grade.

Ryan acknowledges that King's Troop has some improvement to go before making it to the top bracket but also knows he's got a fit and in-form horse.

And he's using the Group Three company to get a guide as to where the colt may fit leading into the autumn.

"He's pretty immature and he's not a big fella," Ryan said.

"He's still got some maturing and growing to do but looking at him you'd think he would improve as he gets older.

"This will also tell us where he fits.

"He's fit, he's well and the best horses in the race are first-up and could be a bit vulnerable."

There are 10 entries for Saturday's race which include Golden Slipper winner Vancouver, one-time Slipper favourite Headwater, Japonisme and Haptic.