Worthington began his career as a forward for Huddersfield Town in 1966 before playing for Leicester City, Bolton Wanderers, Birmingham City, Leeds United, Sunderland, Southampton, Brighton and Hove Albion, Tranmere Rovers, Preston North End, Stockport County and Galway United. Worthington played into his 40s making 757 English League appearances and scoring 234 goals.
He also played in the United States (with NASL teams Philadelphia Fury and Tampa Bay Rowdies), South Africa, Sweden and in English non-League football.
Worthington won eight caps for England in 1974, scoring two goals, during his time at Leicester City.
Worthington further represented England in the 1991 edition of the World Cup of Masters, scoring in the opening round against Uruguay.