He joined Millwall as a striker and made 65 league appearances plus 7 as substitute, scoring 19 goals. He was sold to Gillingham in 1983 and joined Reading later the same year. He formed a successful striking partnership with Trevor Senior and was very popular with the fans. He was part of the team that won the Simod Cup (sponsored name of the Full Members Cup) in 1988, then rejoined Millwall in 1988, but did not get many first-team opportunities.
Horrix was sold to Bristol City in March 1990, but died the following week in a car crash in Berkshire. He had played just three games for the club and was still living in the Tadley area.