The jockey who played a part in starting Atlantic Jewel's unbeaten run will be hoping to end it with an upset win on a rival horse in Saturday's Memsie Stakes.

Stephen Baster rode Atlantic Jewel on debut at Geelong two years ago, winning an 1100m maiden in his only race ride on the now dual Group One winner.

Atlantic Jewel, one of the big spring drawcards, is set to make her long-awaited return from injury in the Group One Memsie (1400m) at Caulfield with her regular partner Michael Rodd aboard.

Baster, meanwhile, will be on Ferlax who is second-up and faces an acid test of his carnival credentials against Atlantic Jewel and an all-star cast including It's A Dundeel and Green Moon.

"This race will tell us where he is compared to the others," Baster said.

Baster rode the Jim Conlan-trained Ferlax to Australian Guineas success and again when the four-year-old warmed up late for seventh first-up in the Aurie's Star Handicap.

"I thought he ran really well in the Aurie's Star and (the winner) Broken has come out and won the Carlyon Stakes so the form is pretty good out of that," the jockey said.

"He's got to step up from where he's been but to me, riding him work, he feels strong and I know Jim is really happy with him."

Atlantic Jewel has won seven from seven and returns for the first time since the All-Aged Stakes in April last year.

Baster said he knew Atlantic Jewel had quality when he rode her to the maiden win.

Conlan says the Memsie will tell him whether Ferlax should go on a Cox Plate path or revert to handicaps such as the Toorak.

"The Memsie is going to be incredibly tough but after it we won't be kidding ourselves. We'll know where we're going," Conlan said.

"Whatever he's got, he'll give us next week. He's in great order for the race."