Blue Diamond Stakes winner Star Witness will need to bring his A-game to Rosehill on Saturday if he is to press on to the Golden Slipper.The undefeated colt is not among entries for the $3.5 million race and trainer Danny O'Brien says connections will only pay the $150,000 late entry fee if Star Witness stands up to be counted in the Group Two Todman Stakes (1200m)."He has to run very well. He has to either win or have a good reason why he didn't," O'Brien said."We're not going to be paying $150

Blue Diamond Stakes winner Star Witness will need to bring his A-game to Rosehill on Saturday if he is to press on to the Golden Slipper.

The undefeated colt is not among entries for the $3.5 million race and trainer Danny O'Brien says connections will only pay the $150,000 late entry fee if Star Witness stands up to be counted in the Group Two Todman Stakes (1200m).

"He has to run very well. He has to either win or have a good reason why he didn't," O'Brien said.

"We're not going to be paying $150,000 unless he is one of the top two or three picks in the Slipper."

The Golden Slipper was not in O'Brien's original plans for Star Witness.

The Blue Diamond was to be the youngster's final run before a spell but he did so well during a brief stint at O'Brien's farm the trainer had a change of heart.

"I wasn't going to put him in the paddock until the end of March because he wasn't going to race until September but he did so well in his two weeks there (O'Brien's farm) that we decided to find him another race for the season and obviously the logical one to target was the Slipper," he said.

Star Witness arrived in Sydney last week and is being stabled at Rosehill with Chris Waller.

The colt worked on the course proper there on Tuesday and while he pleased the stable, O'Brien said only race pressure would reveal if Star Witness handled the reverse way of going in Sydney.

Regular rider Nicholas Hall, who will also be making his Sydney debut at Rosehill, again has the mount in the Todman with Star Witness drawing ideally in barrier five.

"That's great, he drew poorly in the Blue Diamond but he was able to overcome that and hopefully with a good draw on Saturday he can have a better run in the race and we'll see a good result," O'Brien said.

A final field of 13 was paid up for the Todman, including Black Opal Stakes winner Decision Time.

He is also unbeaten and his connections have indicated he needs to finish in the top two in the Todman to convince them to pay the late entry fee for the Slipper.

David Payne has accepted with Masquerader, an impressive midweek winner on debut earlier this month, while David Hayes will start Legalistic who was eighth to Star Witness in the Blue Diamond.

The winner of the Todman is guaranteed a Slipper start provided they are paid up for the Easter Saturday feature.