Two mares pivotal to trans-Tasman trainer John Sargent's plans to enhance his presence in Sydney this summer will face key tests at Warwick Farm on Saturday.

Sargent is chasing his first stakes win out of his Warwick Farm satellite operation with Fromelles who tackles the Listed ATC Cup (2200m) on the back of an encouraging last start third.

Holy Moly, who brought up Sargent's first city win from his Sydney base three weeks ago, will push her claims for a possible start in the Group Two Villiers Stakes when she lines up in the Thankyou Mick Rolfe Handicap (1300m).

Last season's champion New Zealand trainer opened his Warwick Farm stable in August and has 12 horses in work.

He has pinpointed Fromelles as a staying mare with the potential to give the new venture the kick-along it needs.

"She has been progressing well and hit the line nicely last start (over 1900 metres)," Sargent said.

"She's a stakes winner at home in the Rotorua Cup so she's got a bit of class about her.

"She has finally matured this year which is why I brought her over here, as well as trying to kick the stable off here with a nice stayer."

Sargent said races such as Saturday's and the Group Three Summer Cup (2400m) were ideal targets for Fromelles.

"She's not a carnival horse against the top weight-for-age stars but this is a very good level for her," he said.

"She's one of the horses that will hopefully get us away here in Sydney.

"I've got a dozen horses in at the moment here and hopefully I'll get some more over (from New Zealand).

"I'm just progressing slowly, getting the systems right and the staff right and just building it up."

Blake Shinn takes over from the suspended Nathan Berry on Fromelles and he partnered the mare in a hitout on Tuesday morning.

Holy Moly has been kept to fillies and mares company for her second-up assignment after a narrow first-up win at the track.

"She's gone up four kilos and drawn a shade wide but she's got a touch of class, so I'll see how she progresses as to where she goes next," Sargent said.

Fromelles is at $6.50 in betting while Holy Moly is a $6 chance in her race.

"If they are going to progress to better grades you would hope they run well on Saturday," Sargent said.