Andy Gath is a lot more confident of winning the $1.25mil Group 1 Nullarbor than he was when he left home almost a week ago with stable star Catch A Wave.

The former Miracle Mile winner and millionaire pacer showed he was right on target for Australia's second-richest race on Friday night when he opened his WA raid with a terrific fourth from a back-row draw at Gloucester Park last Friday.

"Other than winning, we couldn't have asked more of him," Gath said. 

"We wanted to sit back given where he was at, but they absolutely walked up front and for him to come three-wide himself and get so close (fourth, beaten 6.8 metres) was huge.

"Kate (Gath, driver) said he was all-out on the line but kept digging in."

"They ran home in 55.2sec, and he made up a stack of ground out wide, too."

Champion local driver Gary Hall Jr., who knows and drives Gloucester Park better than anyone, backed up Gath's assessment.

"You can't go any better than what he did, believe me. They went 27.2sec down the back, and he was making up ground, and he kept making ground around the last bend when they were flying. Not many horses can do that," he said.

"It's a great sign for him next week. You couldn't ask any more of him. If he was my horse, I'd be thrilled."

Gath revealed Catch A Wave didn't eat for his first two days after being flown from Sydney to Perth and missed a planned fast workout last Wednesday.

"We jogged him instead of fast-working him because he wasn't eating, and we thought a serious hit out could do more harm than good," he said.

"It wasn't an ideal lead-in to that first run, but it's the benefit of having a lead-up race and getting over there 11 days before the big one (Nullarbor).

"He's come through it really well. He seems great."

"His record shows that he always performs better when he backs up week to week. Most of his biggest wins have come doing that."

"We're heading in the right direction and with another few good days, he should be at his absolute top for Friday night."

Gath is so pleased with Catch A Wave that he's not even sweating about Tuesday's barrier draw.

"No, I don't really care where we draw. I don't know what barrier I'd take if you offered me. Maybe one, and I guess we'd prefer not to draw right out in seven, eight or nine, but I'm not losing any sleep over it."

Catch A Wave is one of three eastern state raiders in the Nullarbor, which was run for the first time last year and NSW pair Betterzippit and Spirit Of St Louis ran the quinella.

Spirit Of St Louis is back for another crack before he departs for the USA to continue his career, while Betterzippit's trainer Jason Grimson is trying to go back-to-back, this time with the emerging Hot And Treacherous.

The field was finalised when Swandoo Racing settled on one of its own horses, Blitzembye, to run in its slot.

It followed with confirmation that Minstrel would run for Team Bond, Jumpingjackmac for Gary Hall Sr/Steve Waters and Justin Prentice Racing went with Mighty Ronaldo.

The pre-draw market shows how open the Nullarbor is, with Minstrel a favourite at $4 from Hot And Treacherous and Lavra Joe ($5), Jumpingjackmac and Spirit Of St Louis ($7) and Catch A Wave ($7.50).