Secret Admirer will be a Caulfield Cup runner but who will ride the mare in the $2.5 million race is a mystery.

Confirming Secret Admirer would be sent to Melbourne later this week, trainer Grahame Begg said a decision on a Caulfield Cup jockey wouldn't be made for a few days.

"We'll be sorting (the jockey situation) out in the middle of the week," Begg said.

Begg reinstated the Caulfield Cup at the forefront Secret Admirer's spring agenda when the two-time Group One winner ran on strongly to finish fifth to Fat Al in the Epsom Handicap on Saturday.

In a race where the first four finishers came along the fence, Begg said he was delighted Secret Admirer was able to finish less than 2-1/2 lengths from the winner after making her run wide out on the track.

"I thought she ran very well and to me she is racing as if she needs a lot more ground," Begg said.

Secret Admirer has raced four times this campaign with James McDonald and Corey Brown sharing the riding duties.

McDonald rode Secret Admirer in the Epsom when the five-year-old was having her third successive start at 1600m.

Although the Epsom is generally an unconventional platform to Caulfield Cup success, it has twice in modern times provided the winner.

In 1997, Might And Power finished almost the same margin from the winner as Secret Admirer when he rebounded for a spectacular 7-1/2-length Caulfield Cup victory.

Earlier, Imposera, as a four-year-old mare, was beaten a half-head in the 1988 Epsom before a heart-stopping win at Caulfield a fortnight later.

But there was a difference to Imposera's campaign because she raced in the Caulfield Stakes in the week between the Epsom and the Cup.

Secret Admirer has 53kg in the Caulfield Cup and she is a $51 chance with most Australian betting agencies.