It seemed the only place to be in Sydney on Tuesday was the Inglis sale yard where even NSW Premier Barry O'Farrell turned up to witness the history-making $5 million sale of Black Caviar's half-brother.

O'Farrell said he was thrilled to witness the sale but would not be able to make it to Randwick on Saturday to see champion Black Caviar race in the TJ Smith Stakes.

"It was great theatre and better than any musical dramas I have seen lately," O'Farrell said.

"Unfortunately I have other commitments and I won't be there on Saturday."

The premier said he appreciated Black Caviar as much as anyone but also risked the wrath of many when he suggested she could make history of a different kind on Saturday.

"The only thing better than a Black Caviar victory will be if Sydney is known as the place where Black Caviar was beaten by a horse with Jim Cassidy on its back," he said.

The horse in question is the John O'Shea-trained Sea Siren, the winner of six of her 12 starts compared to Black Caviar who is aiming for 25 from 25 in the Group One sprint.