Haislip was selected by the Milwaukee Bucks as the 13th pick of the 2002 NBA draft. During his rookie year Haislip was inserted into the starting line-up for the final nine games of the 2002–03 NBA season. When the playoffs started he was relegated to the bench. He remained a bench player with the Bucks for his first two seasons until being placed on waivers on November 4, 2004. He was signed by the Indiana Pacers during the 2004–05 season in order to fill the team's gap at power forward, due to the 15-game suspension of Jermaine O'Neal.