Kozluk made a total of 47 appearances in 2003–04, as the Blades recorded an eighth-place finish, during which he also scored the second goal of his career when he knocked one past Stoke City's Ed de Goey at the Britannia Stadium on 1 November. Injuries at the start of the season meant that Kozluk lost his place in the first team missed the whole first half of the 2004–05 campaign, the inaugural season of the Championship. He was allowed to join Championship rivals Preston North End on a one-month loan in January 2005 where he played in one FA Cup and one league games for the Lilywhites before returning to Bramall Lane where he played a further nine games before the end of the season.