Ralph Manning apprentice Ashvin Goindasamy, 20, was knocked out in a fall from a maiden at Te Awamutu, Wednesday.
His mount in the seventh, Castlereigh, blundered and clipped heels, unseating Goindasamy.
He now faces a lengthy break from action, the stand-down period depending on the severity of the head knock.
His mishap comes at a time when he was beginning to establish a name for himself in New Zealand, including a double on Donna Anne Billy..
Apart from concussion, he suffered no further injury.
He joins a large number on the injured list, including,Tina Comignaghi. Kylie Williams, Jordan Nason and Sarah Macnab