He scored 51 goals and 78 assists for 129 points in 66 games to finish fifth overall in OMJHL scoring. The team's captain in his final year, Reinhart won numerous team honours during his four years in Kitchener including three awards for having the "best defensive ability" on the team. Professional The Atlanta Flames selected Reinhart with their first round selection, 12th overall, at the 1979 NHL Entry Draft. Though he had been set to join Team Canada for the 1980 Winter Olympics, the Flames convinced Reinhart to sign with the team and begin his professional career instead. Joining the Flames for the 1979–80 NHL season, the 19-year-old Reinhart became the youngest player to appear for the team at that point in franchise history. He appeared in 79 games for Atlanta, finishing as the team's highest scoring defenceman. His total of 47 points was second to Ray Bourque for the overall lead amongst rookie defencemen. Transferring to Calgary along with the franchise in 1980–81, Reinhart improved to 67 points during the regular season and tied for the league lead in playoff assists with 14. He was named to the Canadian entry for the 1981 Canada Cup tournament, but suffered an ankle injury and appeared in only two games. He remained an offensive catalyst for the team, scoring 61 points in 1981–82 and set a franchise record for points by a defenceman with 75 in 1982–83. His career total of 250 points also set a Flames franchise record for a defenceman. He returned to Team Canada following both seasons to play in the World Championships. He won bronze medals with the team in both 1982 and 1983, and was named Team Canada's top defenceman in 1983. Reinhart suffered a serious injury midway through the 1983–84 season. Skating behind his net during a game against the Winnipeg Jets, his skate caught a rut and he twisted his back as he fell. He had to be carried off the ice on a stretcher, and was initially diagnosed with back spasms. He was later diagnosed as having suffered a herniated disc. He missed 51 games as a result of the injury, but scored a goal and an assist on his return, a 4–1 victory over the Hartford Whalers. Despite missing the majority of the season, Reinhart was the Flames' offensive leader in the 1984 playoffs, leading the team and finishing first amongst all players