KEY POINTS:
Michael Walker will have to wait a while to break Lance O'Sullivan's mark of riding the fastest 100 winners in a season.
Walker looked a good thing to achieve the feat at Te Aroha today, but the country's leading jockey suffered significant groin strain on Sunday, which worsened riding at yesterday's Cambridge barrier trials meeting.
"His doctors advised him not to ride for the next three days," said his manager, journalist Aiden Rodley.
