Morris was born in Blackpool, Lancashire, during his father Colin's time with the town's club and followed his father into football. He began his career with York City's Centre of Excellence before becoming a trainee at Sheffield United. He signed a professional contract with United on 24 December 1997 before making 26 league appearances and scoring six goals for the first team. This caught Derby County's attention and in the winter of 1999 he transferred for a then club record fee of £3 million, making him the 4th most expensive teenager in British football history. During his time at Derby County he scored 17 goals in 92 league games, including playing in the famous 1–0 win at Old Trafford vs Manchester United, and scoring the winning goal against Spurs. He then had a short loan spell at Huddersfield Town, where he scored once against Barnsley.