Blake Shinn has some unfinished business with Junoob, a situation he hopes to rectify in the Summer Cup at Randwick.

The jockey was aboard when Junoob finished first past the post in the 2014 Metropolitan Handicap, only to have the Group One result stripped after the horse returned a positive swab.

Saturday's Group Three Boxing Day feature isn't held in the same esteem as the Metropolitan but a win would still deliver Shinn a sense of satisfaction.

"I won the Metrop on him and it was taken away so it would be good to get one back on Saturday," Shinn said.

Junoob struggled for form at his subsequent preparation in the autumn but returned to the winner's list last month in the Ballarat Cup.

He carried 60kg to victory in Victoria and has 61kg to contend with at Randwick, although Shinn is more concerned about track conditions than weight.

Heavy rain early in the week and the possibility of more showers has almost guaranteed the Summer Cup will be run on rain-affected ground and Junoob's best performances have been on firmer surfaces.

"His best form isn't on wet tracks so he's a horse who needs some drying weather," Shinn said.

"But it's a small field and he's the best horse in the race."

The Summer Cup will be Junoob's first appearance in more than a month and trainer Chris Waller admits his biggest challenge has been keeping the eight-year-old fit.

He hopes he has achieved that by giving the horse a recent barrier trial.

"We've done everything we can to keep him fit but not flatten him," Waller said.

"The trial is a big help, he looks sharp and he's back in winning form."

Waller wasn't as successful in his quest to prepare Telepathic for the 2000m of the Summer Cup.

The mare was nominated but will contest a 1600m race on Saturday's program.

Waller said Sydney's wet weather had forced him to miss a crucial gallop with Telepathic on Tuesday and she will instead be targeted at next month's Gosford Cup.

"I didn't think she was fit enough to run a good, strong 2000 at Randwick on a soft track," he said.

"She gets a really good chance to win a mile race on Saturday and she'll be hopefully fit and ready to run a really strong 2000 at Gosford."

Along with Junoob, Waller will also saddle up I'm Imposing in the Summer Cup, a race the horse has won for the past two years.