"Ultimately, you are what your record says you are, but I felt in order to get our team to the level it needs to get to, and each individual to the level he needs to get to, that we had to make this decision," Calgary general manager Brad Treliving said.
The Flames were 37-35-10, fifth in the Pacific Division, and missed the Stanley Cup Playoffs by 11 points after making it in Gulutzan's first season.
Calgary's home record of 17-20-4 was the fourth-worst in the NHL, and their power play, at 16.0 percent, was tied for 28th. The Flames also scored an NHL-low 61 third-period goals.
"We underperformed," Treliving said. "When you go through the process of underperforming, you pull everything. It starts with myself, player decisions, personnel decisions. You go into the players' performance, who played well, who didn't and why?"