Premier Melbourne trainer Darren Weir is sending two of his spring hopefuls on Sydney mission to determine their carnival targets.

Former Japanese horse Tosen Stardom will tackle Winx in the George Main Stakes at Randwick on Saturday with Signoff to run in the Hill Stakes.

Tosen Stardom, to be ridden by Craig Williams, was headed to the Underwood Stakes at Caulfield on September 24 but his owners Australian Bloodstock decided to to run him against Winx to gauge his Cox Plate prospects against last year's winner.

The six-year-old came to Sydney in the autumn for the Queen Elizabeth Stakes but missed the race after a bleeding attack in quarantine.

At his first run for Weir, Tosen Stardom finished an unlucky fourth behind Awesome Rock in the Dato Tan Chin Nam Stakes at Moonee Valley on September 3.

After Saturday Tosen Stardom will head to the Turnbull Stakes at Flemington on October 2.

"Because he didn't have a lot of racing over the autumn I thought having two weeks between runs and then another two weeks would be better for him," Weir said.

"Plus the trip away won't do him any harm. "Hopefully it will tighten him up a bit."

Signoff, fourth in the 2014 Melbourne Cup behind Protectionist, was originally going to Morphettville to run in the Tokyo City Cup before the change of direction.

Weir is happy with the way Signoff is progressing towards this year's Melbourne Cup and says the 2000m Hill Stakes fits in perfectly with the gelding's program.

"There was an 1800 metre Listed race in Adelaide but 2000 metres is better for him and the trip away to Sydney will also be good," Weir said.

"It will get him thinking and also tighten him up a bit."

Palentino and Black Heart will be Weir's representatives in the Underwood Stakes after finishing one-two in the Makybe Diva Stakes at Flemington on Saturday.

"They're both on the path to the Cox Plate but at any stage we can deviate," Weir said.

"It's run by run from now on and if they're not running it (2000m) out strongly we can have a re-think.

"There are plenty of races for them."