John O’Shea says Linebacker’s Doncaster Mile preparation “has gone exactly how we have wanted”.

John O'Shea  is content he couldn't have Linebacker in any better shape for the Doncaster Mile and the rest, he says, is up to the horse.

The colt remains favourite at $6 after coming up with gate 14 at Tuesday night's barrier draw and O'Shea says Linebacker's campaign has been faultless.

"The things we can control we have under control," O'Shea said.

"He is a very fit, healthy horse. Whether we're good enough, we're going to determine that on Saturday.

"The preparation has gone exactly how we have wanted. He will have a couple of nice easy days going into the race on Saturday.

"The horse is in great form, the rider (Zac Lloyd) is in great form and the stable is very relaxed with his preparation."

Three-year-olds have won close to a third of the past 30 renewals of the Doncaster Mile, the latest Celestial Legend last year, and O'Shea has followed a similar template to the one that horse's trainer Les Bridge adopted.

Both claimed the Randwick Guineas and like Celestial Legend, Linebacker has been given a month between runs with a barrier trial in between.

The O'Shea-trained Café Millennium finished third in last year's Guineas and taking a line through him, O'Shea believes the signs point to this year's instalment being even stronger.

"Last year, we ran third in the Guineas and there was about half a dozen of them all going to the line together so I was thinking maybe the Guineas wasn't that strong," he said.

"This year's Guineas, they ran time, there was a long distance from first to last, they went a good gallop."

The unknown is how Linebacker will measure up against more more seasoned rivals but with just 49kg in a spread that has Another Wil topweight with 56.5kg, O'Shea is happy to find out.

"It's a matter of analysing how he lines up against what was a very strong George Ryder Stakes and a very strong All-Star Mile," he said.

"Those horses are probably weighted up to their best in a Doncaster, so we're probably going to have to utilise our weight advantage and hopefully get a position in the running that gives us a chance to be in the finish."

The Doncaster barrier draw didn't have a major impact on markets, Gringotts ($7) and Tom Kitten ($7) both holding their place high in betting after drawing barriers six and one respectively.

Japanese raider Geoglyph eased slightly to $26 after coming up with the outside gate in the field of 20 plus four emergencies.