Danny O'Brien believes the addition of blinkers to Running Tall gives the colt the chance of upsetting odds-on favourite Sepoy in Saturday's Blue Diamond Stakes at Caulfield.O'Brien, who won the $1 million juvenile feature with Star Witness last year, made a good case for the son of Stratum who chased home Sepoy when a 3-1/2-length runner-up in the Blue Diamond Prelude (1100m) at Caulfield on February 12."We couldn't be more pleased with the horse. We've always thought he had the potential of a

Danny O'Brien believes the addition of blinkers to Running Tall gives the colt the chance of upsetting odds-on favourite Sepoy in Saturday's Blue Diamond Stakes at Caulfield.

O'Brien, who won the $1 million juvenile feature with Star Witness last year, made a good case for the son of Stratum who chased home Sepoy when a 3-1/2-length runner-up in the Blue Diamond Prelude (1100m) at Caulfield on February 12.

"We couldn't be more pleased with the horse. We've always thought he had the potential of a Blue Diamond winner," the Flemington trainer said.

"His first run in the spring (third to Arctic Command in the Group Three Maribyrnong Plate at Flemington) was very good.

"He was on the wrong side of the track and just got nosed out.

"First-up in the Prelude, Sepoy was obviously too strong for him but he's a colt that we've been waiting to put the blinkers on and they go on tomorrow.

"I'm very, very confident he's going to run well with due respect to Sepoy who very much deserves to be favourite."

O'Brien said the jump up to 1200m for the first time was a query for the horses that haven't been tried at it - Masthead and Delago's Lad being the only ones to have run at the trip when first and third respectively in the Inglis Premier at Mornington on February 16.

"It's a big step in racing for two-year-olds when they go to 1200 metres for the first time. That extra 100 metres brings a lot of them undone," he said.

"Sepoy looks bulletproof but our horse is going to run very well tomorrow. He's going to run the 1200 metres right out and we're confident he'll be there giving him (Sepoy) a race."

O'Brien said he would be pretty confident of Running Tall winning if Sepoy wasn't in the race and he'd be a $7 or $8 chance rather than his $19 quote with TAB Sportsbet.

"Sepoy has been very dominant," he said.

O'Brien predicted last Saturday's Talindert Stakes winner Anevay would lead from barrier three and Running Tall would be "right up there" from gate one.

"I don't know whether it's going to be a super-pressured race. I'd imagine he'd track Anevay into the race and he'd have to run down Sepoy," he said.

While Star Witness went into the Blue Diamond unbeaten in two starts including a win in the Talindert Stakes (1100m) at Flemington, Running Tall goes in as a maiden, albeit placed at both his starts.

O'Brien said jockey Ben Melham chose to ride Running Tall, who he rode in the Prelude, ahead of the Lee Freedman-trained Atomic.

Melham won the Listed Chairman's Stakes (1000m) aboard Atomic at Sandown at his only start on February 9.

"He is a real two-year-old. He ran all right first-up in the Prelude and he will take good fitness out of that and see him a lot sharper," Melham said of Running Tall.

"That run will tighten him up as he is a big gross colt.

"With the blinkers on I think he is one of the forgotten horses and think he is live top-three chance."

Sepoy dominates the betting at $1.50 ahead of Atomic and Hallowell Belle at $11 with Running Tall best of the rest.