[3][4] Warren arrived in the UK in March 1948 and signed up with the Birmingham Brummies in the National League Division Two.

In sixty meetings that season, Warren was unbeaten by an opponent in twenty five of them and averaged almost eleven points a match.

In the May 1948, just two months after arriving in the UK for a trial with Birmingham, Warren was selected to ride for Australia.

In 1949, despite being in a tougher division he still scored almost ten points a meeting and he qualified for his first World Final.

In early 1951, a severe accident at a meeting in New Zealand left Warren with a triple skull fracture and his career was never to hit the heights of 1950 again.