Randwick trainer Craig Carmody is gearing up for the biggest race of his training career when four-year-old gelding Single lines up in the $2 million Doncaster Handicap at Randwick on Saturday.

The former jockey turned trainer has shown plenty of patience with the listed winner and he is hoping it all pays off in what is one of Australia's premier handicaps.

Carmody has brought the horse along slowly and likes to give the son of High Chaparral a month between his runs, last lining up when winning the listed Sky High (1900m) at Rosehill on March 24.

“It takes him a while to recover after each run, and he loses a bit of condition and 10 days later he puts it back on again,” said Carmody.

“ If you run him 10 days or even two weeks after a race which I have done before without success, he certainly will not run up to his standard.”

Single, who was also nominated for the JRA Plate (2000m), only just snuck into the field on the back of his listed win and has certainly earned his spot in the field after winning six races from 10 career starts.

“He has made the field and that says everything, but it is a huge jump in grade from what he has been racing in.”

“It's hard to deny the connections the opportunity of seeing there horse run in a big race like this and he has earned it.”

With regular jockey Nathan Berry in the saddle, Single has drawn wide in barrier 19 and will have to overcome a very wet track on Saturday, which he has run on once to no avail.

“I am not overly happy with all this rain,” Carmody said.

“He did not run well on a heavy track at the one try he has had on it, but I ran him seven days later after winning at Rosehill, and since we have learnt with the horse that is not the way to go,” he added.

“So it may have been my error or he didn't handle the going, somewhere in the middle of that is the truth and I guess we will find out on Saturday.”

Carmody said his expectations leading into the race are very guarded and he is hoping his charge can handle the going and run a nice race.

“I think I get more nervous (during a race) when I am training than when I used to ride because it is out of my hands.”

“You can put all the foundation in, but Nathan knows the horse really well and rides him particularly well which eases any anxiousness.”

Single was purchased for only $25,000 as a yearling and was sent to Carmody to train before the owners decided to put him back in the ring two years later where he fetched $60,000 by Carmody and other connections.

Single is currently $41 on tab sportsbet fixed odds with Secret Admirer and More Joyous sharing favouritism at $6.