Darren Weir is hoping Stratum Star may be the Group One replacement his stable is looking for as the spring carnival gets into gear.

Weir's spring carnival stocks have taken a hit with injuries to two high-profile horses, Trust In A Gust and Signoff, forcing them to the sidelines.

Last season's premier Melbourne trainer is banking on fringe horses taking the next step.

On Saturday, Weir has Stratum Star stepping up to weight-for-age company in the opening Group One race of the season, the Memsie Stakes (1400m) at Caulfield.

Stratum Star was the first emergency and gained a start after the scratching of Fawkner.

Weir hopes Stratum Star can follow the same route as Trust In A Gust, winner of the 2014 Group One double of the Sir Rupert Clarke Stakes and Toorak Handicap, but it could change if he is successful at weight-for-age in the Memsie.

Stratum Star will be joined by stablemates Dandino and Prince Of Penzance in the Memsie with Stratum Star the pick of the Weir trio.

The four-year-old has firmed from $10 to $9.50 with Boban the $4.80 favourite. Dandino and Prince Of Penzance are outsiders at $61 and $81 respectively.

"He's the best of my three," Weir said of Stratum Star.

"We'll see how he runs on Saturday but he's likely to go to the Rupert Clarke and the Toorak.

"If he happened to win then it might cause a re-think and we'd look at the Makybe Diva, but we'll just get over Saturday first.

"I think he will measure up but I don't want to be getting too carried away just yet."

Stratum Star ran third in the Australian Guineas behind Wandjina in the autumn and returned with a closing seventh to Setinum at Caulfield over 1200m on August 15.

Dandino, runner-up in the 2013 Caulfield Cup, will be having his first run for Weir after suffering a leg injury on the eve of the Caulfield Cup last year when trained by Marco Botti.

"They'll be miles too sharp for him but as long as he's hitting the line I'll be happy." Weir said.

Caulfield was in the soft range on Friday, increasing the chance of Prince Of Penzance running with Weir unwilling to start him on a firm track.