Co-trainer Ben Hayes cannot split So Si Bon and Fifty Stars as the stable's best chances of ending the Melbourne Cup carnival with a Group One win.

The pair will be one half of a quartet of Mackinnon Stakes (2000m) runners for Lindsay Park on Saturday, along with Caulfield Stakes winner Cape Of Good Hope and Harlem, both coming off unplaced efforts in the Cox Plate.

But it is Cantala Stakes runner-up Fifty Stars and fourth placed So Si Bon who Hayes believes will be best suited in Saturday's Mackinnon, which has a capacity field of 16 plus two emergencies.

"It's a very competitive and open race. But I really like the way So Si Bon and Fifty Stars have come out of their good runs in the Cantala," Hayes said.

"They've really bounced out of it.

"There is a bit of rain forecast and that will really suit both of them."

Lindsay Park is chasing its first elite win of the Cup carnival after Fifty Stars was luckless when narrowly beaten by Fierce Impact in the Cantala Stakes last Saturday.

Hayes also says Rostropovich is continuing to please vets in his recovery from a fractured pelvis, suffered during Tuesday's Melbourne Cup.

Rostropovich was rushed to the University of Melbourne Equine Centre after the race and hopes are high the horse can make a full recovery.

"He's weight-bearing and moving around his box," Hayes said.

"He seems really bright in the eyes and he is eating and doing everything right.

"It is a pelvic fracture and they normally take six to eight months for recovery but it's a good prognosis and it looks like, if everything goes to plan, he will be able to race again."