Australia is on the drift in betting for the UK Derby but the favourite's jockey Joseph O'Brien remains excited about his prospects, reports At The Races.

O'Brien and his father Aidan became the first father-son combination to win the Classic in 2012 with Camelot, and 2000 Guineas third Australia heads a four-strong team from Ballydoyle on Saturday.

Paddy Power eased Australia to a best-priced 5-4, but O'Brien jnr said: "I'm really looking forward to it. Ever since he came into the yard and started working he's always been a good horse. He's bred to stay the trip, bred to handle the track and bred to win the Derby which is what you need going to Epsom. It's the ultimate test of a racehorse."

The jockey continued: " You need to have a horse with pace, balance and that will get the trip. It's a funny track to ride at times, with Tattenham Corner and all the different things running down into the straight, it's the ultimate test of horse and rider. It's the race every jockey wants to win.

"He's got plenty of pace, hopefully he'll get the trip but it's an unknown, his mum and dad handled the track well. We're looking forward to it."

The bookmaker reported a couple of weeks ago that "a racing insider told our representative at Sandown that Geoffrey Chaucer absolutely smashed Australia in a Ballydoyle gallop" and the firm are not repenting.

Paddy Power said: "Pundits have yawned and called us 'the grandmasters of PR flim-flam' about our statement on the possible merits of Australia and Geoffrey Chaucer.

"But we're happy to put our money where our mouth is and take on the 'jolly', especially when Aidan is employing the scattergun approach of four runners."

Epsom clerk of the course Andrew Cooper said on Tuesday evening: "We're going to leave it as good at close of play. There was some light rain in the area this morning, just enough to wet the grass, and the going stick is at 7.8, which is an indication of good ground.

"We are forecast showers, maybe starting at 2am or 3am and going on for most of the day. It sounds like they are going to be light, possibly five millimetres, so it's not a deluge. If that's what we get, the ground's not likely to get worse than good.

"Thursday is dry and then it gets warm and more humid, which does leave the chance of rain by Saturday. So we'll see what we get and play it by ear."