In his first season (2004–05), he was voted as the club's Player of the Year after some superb saves throughout the season, including saving several penalties for Leeds in games against Wolverhampton Wanderers, Cardiff City, Burnley and Nottingham Forest. Leeds finished 10 points off the playoffs after a season of rebuilding. In his second season at Leeds he continued his penalty saving prowess, saving one in a 1–0 win away at Stoke City, and Leeds went on to reach the playoff final against Watford with Sullivan again having a decent season. But the playoff final ended in defeat for Leeds, losing 3–0 and Sullivan scoring an own goal.