The Calgary Flames' newest blue-line addition brings a quality often overlooked in today's speed-and-skill game.

Connor Mackey, a WCHA First Team All-Star at Minnesota State this past season, inked a one-year, entry level contract with the Flames on Friday. Mike Hastings, his head coach in college, spoke highly of the 6-foot-2, 205-pound rearguard's physical play.

"He has a little bit of a natural nastiness to his game, where he’ll be aggressive, and the physical piece just came as he continued to get stronger,” Hastings told the Calgary Sun's Wes Gilbertson.

“You need to have an edge to get guys to think about, ‘Do I really want to come in here? Do I really want to get inside the dots? Do I really want to stay at the net?" Hastings added. "That, I think, is the maturation from his sophomore year - when he could have signed - to this past year."

Mackey, 23, tallied seven goals and 24 points in 36 games this past season. He was considered TSN's top undrafted free agent and received interest from 28 of the league's 31 teams, TSN's Frank Seravalli reports.

Calgary also added another college free-agent defenseman to the mix in Colton Poolman. He isn't as highly regarded as Mackey, specifically on the offensive side of the puck. However, he's a finalist for the NCHC defensive defenseman of the year. Seravalli notes he possesses "shutdown capability" and "oozes character."

“They’re not 18-year-old kids - they’re young men,” Flames general manager Brad Treliving told The Athletic's Scott Cruickshank. “They’re big guys, physically strong guys.”

The 24-year-old Poolman tallied 17 points in 31 games last season at North Dakota, where he was the team's captain for two years. He's the younger brother of Winnipeg Jets defenseman Tucker Poolman.

Five Flames defensemen - T.J. Brodie, Travis Hamonic, Derek Forbort, Erik Gustafsson, and Michael Stone - are set to hit unrestricted free agency this summer.