the team they were building. The Flames assigned him back to Colorado, intending that he would play the entire 1983–84 season in the CHL. He was recalled to Calgary on October 22, 1983, after only six games for what was expected to be a short stint with the NHL team. Instead, he established a place with Doug Risebrough and Richard Kromm as Calgary's top defensive line and never returned to the minors. Patterson scored his first NHL goal on October 26, 1983, against goaltender Mike Liut of the St. Louis Blues. He finished with 26 points in 56 NHL games in his rookie season, then scored what were ultimately career highs with 22 goals and 43 points in 57 games in 1984–85. Patterson had 21 goals in the first 40 games of the season before missing 23 games in the second half due to knee and shoulder injuries. While he was regarded as a top defensive forward for the Flames, he was frequently forced out of the Flames' lineup due to injury during his career. Patterson missed time in 1986–87 due to concussions, and played in only 39 of Calgary's 80 games in 1987–88. Patterson's skills as a defensive forward were recognized in the 1988–89 season when he was named a finalist for the Frank J. Selke Trophy. He played in a career-high 74 games, recorded 38 points and his plus-minus of +44 was the third highest in the NHL. Playing on a line with star scorers Doug Gilmour and Joe Mullen, Patterson was regarded as the team's "unsung hero" and played a grinding role to generate opportunities for his teammates. In the 1989 Stanley Cup Playoffs, Patterson appeared in 22 games and recorded a career high 13 points as the Flames defeated the Montreal Canadiens in the final to win the franchise's first Stanley Cup championship. Injury problems returned in 1989–90 as, after recording only eight points in 61 games, Patterson's season was ended when he broke his ankle on March 24, 1990. His attempted return for the 1990–91 season was halted when he suffered torn knee ligaments during a pre-season game against the Toronto Maple Leafs. The injury caused him to miss the entire regular season, and he returned to appear in only one playoff game. Unsure how Patterson would return after missing the season, the Flames opted to trade him to the Buffalo Sabres prior to the