Farrell played for Leeds Rhinos at second-row in their 1998 Super League Grand Final defeat by the Wigan Warriors.
Whilst in his first year at Halifax the sacking of Tony Anderson opened a new career for "Faz" as he was asked to become temporary coach until the end of the year. After saving the club from relegation the following season Farrell took the club within a whisker of a place in the grand final. Losing out to Castleford Tigers. The year after was less successful for Farrell though, after a poor series of results including a club record defeat by the Hull Kingston Rovers, "Faz" eventually lost his job.