The bush trainer who gave Samantha Clenton her first break in racing expects to cash in on her emergence as a leading apprentice when they team up at Randwick on Saturday.

Port Macquarie-based Tas Morton insists he has fleet-footed mare Nuclear Class ready to make a first-up impression in the James Boag's Premium Handicap.

For Morton, having Clenton in the saddle would make a city win even sweeter.

"Samantha started her career with me, she spent the first twelve months of her apprenticeship in the stable," Morton said.

Morton is backing Clenton to go all the way and make a decent living out of racing now she has been able to get her weight under control.

Given Clenton's background in horses, Morton said her sudden rise in Sydney's riding ranks since linking with the Kris Lees stable came as no surprise.

"She has grown up with horses like all the good jockeys," he said.

"They become horsemen and horsewomen before they become jockeys and Samantha is no exception."

Clenton is listed as riding at 54.5kg and she won't be able to claim her full 3kg on Nuclear Class.

But her allowance might still be enough to give Nuclear Class a winning edge if Morton is as good a judge of a horse as he is of a jockey.

"We had her ready for the Razor Sharp (last month) but as it turned out we didn't have her ready because she had a couple of setbacks," Morton said.

"We have got to be careful where we run her but we've set her up for this race."

Nuclear Class had Clenton on board in her Hurricane Stakes win during the Newcastle Gold Cup carnival.

And while Nuclear Class hasn't raced since that victory over 900m in September, Clenton has been riding high in the popularity stakes with Sydney's trainers, including the indomitable Chris Waller.

Nuclear Class is pressing for favouritism in a congested market at the top of betting which includes Inside Job and Thermal Current.

Thermal Current is also an acceptor for the Listed Kensington Stakes at Flemington for which the Peter Moody-trained sprinter is second favourite.