Horsfield's first Premier League goal came in the September 2002 local derby defeat of Aston Villa. He also scored in the return fixture at Villa Park, an eventful game in which he ended up keeping goal when Nico Vaesen was injured after Birmingham had used all their substitutes. Horsfield missed games through suspension and surgery, and was frustrated by manager Steve Bruce preferring to use him as a specialist substitute; after he came on to score a late winner against local rivals West Bromwich Albion, Bruce described him as "a manager's dream", saying that "when you're tiring, the last thing you need is Big Horse rampaging at you". Starting alongside World Cup-winner Christophe Dugarry late in the season, the pair formed "an unlikely combination, brilliance from Bordeaux alongside a brickie from Barnsley, but Horsfield's robust approach has complemented Dugarry's more delicate touches"; their partnership produced four wins and a draw from the last six games.