The international raiders have tightened their stranglehold on the Melbourne Cup with the news last year's winner Efficient had been ruled out through injury.Leviathan owner Lloyd Williams still has Zipping and C'est La Guerre in the Cup but said the injury to Efficient's off-front leg was devastating for the stable with the grey rated the best chance of upsetting the Europeans."It's a tragedy for us but more so his personal attendant Angie Hill who has been looking after him for 51 weeks gettin

The international raiders have tightened their stranglehold on the Melbourne Cup with the news last year's winner Efficient had been ruled out through injury.

Leviathan owner Lloyd Williams still has Zipping and C'est La Guerre in the Cup but said the injury to Efficient's off-front leg was devastating for the stable with the grey rated the best chance of upsetting the Europeans.

"It's a tragedy for us but more so his personal attendant Angie Hill who has been looking after him for 51 weeks getting him ready for this event and she got within six days and this is what has happened," Williams said.

"I feel sorry for Angie."

Efficient's withdrawal has further cemented the claims of Irish stayer Septimus who is the solid $4.50 favourite with TAB Sportsbet ahead of English horse Mad Rush ($5.50), New Zealander Nom Du Jeu ($11), Godolphin's Caulfield Cup winner All The Good ($11) and Irish mare Profound Beauty ($13).

Zipping and C'est La Guerre lead the Australians at $16 with bookmaker Sportingbet Australia offering $1.30 that the Melbourne Cup winner will not be trained in Australia.

"We are currently betting $1.30 that the winner will not be trained in Australia and that actually still looks value," chief executive Michael Sullivan said.

Aidan O'Brien, the trainer of Septimus, has no doubt he deserves to be favourite.

"Septimus is a horse that tries extremely hard," O'Brien said.

"Honolulu and Alessandro Volta, they save a little bit, they're lazy and they only give what they need to.

"But Septimus, when you ask him, he gives it all."

The desire and the honesty of the horse regarded as Europe's best stayer went on full show in the Irish St Leger last month, a race Septimus won by 13 lengths.

"Even though he won that easily, I don't think he could have won by 14 lengths," the trainer said.

"He gave it all, every drop he left out there on the track."

As admirable as Septimus' desire may be, it has left him a couple of kilograms lighter than O'Brien would like.

It is only a slight concern, but it also reveals something of how the trainer's 22 Group One races have been won this year.

"I won't be changing plans, but it's something you keep in your head," he said.

"Just to be gentle with him."

While Septimus is the horse his trainer has the most faith in, the other two have a part in the Cup plot.

"We're going to hope that Alessandro Volta, with a light weight on his back, will step up," he said.

"With Honolulu, we know that he stays well and we just hope that he's quick enough.

"And with Septimus, we're just going to hope that with the big weight, that he might be able to do it."

Efficient's withdrawal, coupled with trainer John Sargent's announcement Red Ruler would miss the Cup, elevated Geelong Cup winner Bauer to 24th in the order of entry and the only threat to him making the field is the participation of the winner of Saturday's Saab Quality which gains automatic entry.

Another English horse, Yellowstone, is back on track for a Cup start after the horse's campaign was plunged into doubt on Tuesday by a hip injury.

Trainer Jane Chapple-Hyam said the horse was again a definite starter.

"We'll get there," Chapple-Hyam said.

"He was fine this morning, he cantered along nicely and the best thing was that he trotted up alright afterwards."

Yellowstone injured his hip when he became cast in his box on Monday afternoon and will be examined by veterinary officials again on Friday.