Bjorn Baker is hoping lightning strikes twice when Impavido encounters a wet track for the second time in the Group One $1 million Randwick Guineas.

The three-year-old gelding won on debut at Kembla Grange in late January on a soft 5 and with rain continuing in Sydney, heavy ground is guaranteed at Randwick on Saturday.

Impavido is rated a $21 chance for Saturday's 1600m-feature coming back in distance from his last-start third in an 1800m-benchmark race at Rosehill on February 22.

"He was probably unlucky not to be closer at the finish. He's coming back from 1800 which I think will be a positive for him on a wet track," Baker said.

"He's handled a wet track before. He's bred to get a wet track being by High Chaparral out of a Zabeel mare (Assertion)."

Tye Angland will ride Impavido which Baker hopes is an omen.

"Tye ran a third for me in the Randwick Guineas on an 80-1 shot (Gold Ambition) last year. I think he's a definite hope at the price," Baker said.

The trainer was hopeful rather than confident about the stable's other runner, $101 chance Captain Duffy, who he acquired from South Australian trainer Phillip Stokes last October.

The colt beat just one runner home in his first start for Baker when he started from the outside gate in a field of 10 in the Group Three Spring Stakes (1600m) at Randwick on February 13.

"No doubt he needed that run first-up," Baker said.

"He had a torrid run from the gate and he probably wasn't fast enough. It's three weeks between runs and we've been able to do plenty with him.

"He's got a little bit of wet track form but this is another jump up," Baker said.

Captain Duffy ran 13th in his solitary Group One experience in the Victoria Derby, his last start before changing stables.

The Chris Waller-trained Comin' Through is the TAB's $4.60 favourite ahead of Inference (Hawkes Racing) and Man from Uncle (Anthony Cummings), who are both at $6.

Randwick was rated a heavy 9 on Friday after after 22mm of rain fell in the previous 24 hours. More rain is forecast on race day but it is expected to ease in the afternoon.