The native of Trochu, Alberta starred with the Three Hills Braves and the Olds Grizzlies before graduating to the WHL's Regina Pats in 1987-88. Haller often dominated at both ends of the ice and was chosen 14th overall by the Buffalo Sabres at the 1989 NHL Entry Draft. After spending most of his first pro season with the AHL's Rochester Americans, the young blueliner was one of the Sabres' best players during a first round loss to the Montreal Canadiens in the 1990 playoffs.
After establishing himself as a regular on the Buffalo defence, Haller was traded to the Habs in March, 1992 for veteran rearguard Petr Svoboda. The next season he scored a personal high 11 goals and was a member of Montreal's Stanley Cup championship. When the team regressed in 1993-94, management made a few changes including the trading of Haller to the Philadelphia Flyers.
During his 2 1/2 years with Philly, Haller helped improve the club's fortunes in the NHL standings. The high point was the 1995 playoffs when the Flyers reached the Eastern Conference final. In December, 1996, Haller was sent to the Hartford Whalers as part of the package for star defenceman Paul Coffey. He remained with the franchise when it relocated to Carolina in 1997 then played two years with the Mighty Ducks of Anaheim. After signing as a free agent with the New York Islanders in July, 2000, Haller only played 31 games over the next two seasons and has since been away from the game.