Leon Corstens believes there has been sufficient improvement in Starspangledbanner to warrant taking on big guns Rostova and Real Saga in the Group One $1 million Blue Diamond Stakes at Caulfield.The Choisir colt has ample pace and is expected to lead Saturday's 13-horse field after drawing barrier one.He has led in both his starts to date for a debut victory in the Inglis Juvenile (1000m) at Moonee Valley on Cox Plate day last spring and a first-up third, beaten six lengths, to Real Saga in the

Leon Corstens believes there has been sufficient improvement in Starspangledbanner to warrant taking on big guns Rostova and Real Saga in the Group One $1 million Blue Diamond Stakes at Caulfield.

The Choisir colt has ample pace and is expected to lead Saturday's 13-horse field after drawing barrier one.

He has led in both his starts to date for a debut victory in the Inglis Juvenile (1000m) at Moonee Valley on Cox Plate day last spring and a first-up third, beaten six lengths, to Real Saga in the Blue Diamond Prelude (1100m) at Caulfield on February 8.

However the trainer doesn't want the colt ripping and tearing in Saturday's 1200m feature.

"I think he's improved substantially. I think he's going to strip a lot fitter," Corstens said.

"I'm hoping he switches off a bit better as he was inclined to overrace a little bit (first-up) and in a race like the Blue Diamond you can't afford to do that."

Starspangledbanner is an $18 chance on TAB Sportsbet's fixed odds market and will be ridden by Vlad Duric whose only Blue Diamond ride to date was 12th on Marveen last year.

Corstens has had three unplaced runners in the Blue Diamond in Bardego (12th in 2002), Danaurum (sixth in 2004) and Siennas Fury who was eighth last year.

Starspangledbanner is one of two runners in the race in which high-profile owner Tony Santic has an interest.

He bred the colt under his Makybe Racing and Breeding banner and retained a share in him, while he bred and races the Mick Price-trained Corsaire ($26) who is also expected to race forward.

Price said the Anabaa filly surprised him when she won at her debut in the Merson Cooper Stakes (1000m) at Sandown last spring.

Corsaire resumed with a two-length second to Rostova in the Blue Diamond Prelude for fillies after leading at the top of the straight.

"After she won the Merson Cooper we upped our opinion of her and set her for the Blue Diamond," Price said.

"I believe she's still an immature filly who'll make a lovely three-year-old, I think she's some sort of Thousand Guineas filly so I don't want to give her too many starts as a two-year-old.

"She's fit, sound, been primed into the race. She's at her top and will be thereabouts.

"I just hope they crawl early."

Unbeaten filly Rostova is $2.60 favourite and has been well supported since drawing ideally in barrier six on Tuesday, while Real Saga is at $3.20, Come Hither at $10 with Reward For Effort and Irish Lights next best at $15.