Solzhenitsyn's Mackinnon Stakes failure remains a mystery to his trainer and jockey who will be relying on what they do know about him in the Emirates Stakes.

What is clear to both Robert Heathcote and Nash Rawiller is that the seven-year-old dual Group One winner is a superior middle-distance performer and can bounce back at Flemington on Saturday.

Solzhenitsyn finished a long last of the nine runners in last Saturday's Mackinnon after being eased down by Rawiller.

In the absence of any other explanation, the consensus is that Solzhenitsyn must have choked down and will wear a tongue tie on Saturday.

"We are 99 per cent certain he choked down but there's really no way to be sure," Heathcote said.

"There's not veterinary reason for what happened and he pulled up well.

"Whether it was because he was restrained in what was a farcical pace but he never got into his rhythm.

"We've worked him in the tongue tie all week and he's taken to it like a duck to water.

"Hopefully that solves things because he's too good a racehorse to have run like that."

The Chris Waller-trained Epsom Handicap winner Boban is favourite ahead of Toydini who finished third in the Randwick mile while Solzhenitsyn is on the fifth line of betting.

French horse Havana Gold will miss the race due to injury, adding to a week trainer Mikel Delzangles might like to forget.

Delzangles will front an inquiry on Friday over ulcer treatment given to Dunaden on the morning of Tuesday's Melbourne Cup.

Dunaden, winner of the 2011 Melbourne Cup and 2012 Caulfield Cup, failed to earn top 10 prize money when he finished 11th in the Cup won by the Gai Waterhouse-trained Fiorente.

Waterhouse faces similar charges over paste administered to the hooves of her other Cup runner, the unplaced Tres Blue.

Delzangles scratched Havana Gold on Thursday morning, saying he had knocked his leg in his stable overnight.