So You Think’s half-brother Now You Know will take to the track for his debut run at Flemington this Saturday.

Steven Arnold will be the jockey to launch Now You Know’s career when he competes in the 1,400 metre SecondBite Plate.

Now You Know was purchased by trainer Danny O’Brien for $260,000 at the Karaka sale in New Zealand, just months after So You Think won his second Cox Plate.

While Now You Know is set to make his racing debut this weekend, O’Brien believes that we won’t see the best of his until the spring.

“He is a very nice horse but still immature and certainly he’s going to improve a lot as a three-year-old,” O’Brien said.

“He is a 2000-metre horse in the making hence he’s running first-up over 1400 metres but I’ve been happy with his development so far and we are hoping that he can show us some good signs on Saturday.”

O’Brien is hoping that Now You Know will demonstrate that he has the ability to be aimed at some of the spring carnival’s best staying races later in the year.

“Ideally he will have this run and maybe one more and if he shows enough we could then set him for some targets in the spring,” O’Brien said.

“He has just got to justify is he is up and about and good enough.”

Despite his relation to the great So You Think, O’Brien has conceded that his other representative in Saturday’s race, The New Boy, has a better chance of winning due to the fact that he possesses race experience.

“(The New Boy) is the stable elect,” O’Brien said.

“He knows what it is all about and should have won both his starts so I am expecting him to be hard to beat.”

Now You Know will have big shoes to fill, with his older brother So You Think winning his European debut by an astonishing 10 lengths on Monday.