Unchain My Heart has been scratched from Saturday's Lexus Stakes with trainer David Hayes taking the gamble the mare makes the Melbourne Cup field.

After the withdrawal of 2012 Cup winner Green Moon from the Cup on Saturday with a cracked hoof, Unchain My Heart moved up one place to 23rd in the ballot order.

After hearing Green Moon was out, Hayes applied to stewards to scratch Unchain My Heart, a two-time winner over the 3200 metres of the Cup.

Stewards granted his request but the mare can still miss a place in the 24-horse Cup field with the winner of the Lexus earning an automatic place.

Shoreham, who runs in the Lexus, can also leapfrog Unchain My Heart even if he doesn't win but finishes second or third.

Amralah could also go ahead of the mare with a top three finish in the Mackinnon Stakes later on Saturday.

"I reckon if she ran today it would not enhance her chances for the Cup, knowing her it wouldn't help," Hayes said.

"She's a filly that likes her races more spaced than three days."