Liam Birchley is in a race against time to get Pop `N' Scotch fit to compete at The Championships in Sydney after a delayed start to the horse's preparation.

Pop `N' Scotch will step out in the Marsh Advantage Insurance Handicap (2020m) at Doomben on Saturday after he was well beaten over 1350m at his first start for the trainer last month.

The sprint race wasn't in Birchley's original plans but wet weather in Brisbane forced his hand.

"You can ignore his first-up run for us because we had him set for a 1600-metre race and it got washed out," Birchley said.

"It put us behind and we had to start somewhere - the 1350 metres was really our only option. It was far too short for him."

Originally raced by Patinack Farm, Pop `N' Scotch was bought for $220,000 by clients of Birchley at a dispersal sale last year.

The horse has shown tremendous staying promise and ran second in the Queensland Cup last July in what was the best performance by a three-year-old in the 3200m race since Sunset Gem won it in 1970.

For that reason, Birchley had no hesitation stepping Pop `N' Scotch up sharply in distance for Saturday's race.

The horse has been pencilled in for a trip to Sydney for next month's Chairman's Handicap at Randwick but Birchley says he needs to race well at Doomben to confirm interstate plans.

"If you look at his form he is a pretty promising stayer. Not too many three-year-olds start equal favourite in a Queensland Cup and that was at the end of a 10-run, two-state campaign," Birchley said.

"But we are probably a run behind because of the washed out race. We will know after Saturday if he is ready for Sydney but there is always the winter."

In-form jockey Larry Cassidy takes over from Jeff Lloyd on Pop `N' Scotch.

Cassidy, who rode a double at the Gold Cost last Saturday, feels he is nearing the form which resulted in him winning multiple Sydney jockeys' premierships.