The Vegas Golden Knights are acquiring prized Calgary Flames defenseman Noah Hanifin as they chase a second straight Stanley Cup championship, a source told ESPN on Wednesday, confirming a Sportsnet report.

Hanifin's contract carries a $4.95 million cap hit. He was scheduled to become an unrestricted free agent this offseason, having informed the Flames he was going to test the market. There's speculation the Golden Knights will sign Hanifin to a contract extension.

Hanifin, 27, is in his ninth NHL season, all of them with Calgary, who selected him fifth overall in the 2015 NHL draft. The left defenseman has 35 points in 61 games this season and is averaging 23:46 in ice time.

Hanifin is 27th among defensemen in points over the past three seasons, plays well in transition, and defensively is great on puck retrievals and zone exits with possession. He played in all situations for the Flames, including on their top penalty-killing unit.

The Boston native can contribute moderately on the offensive end, but his true value is swallowing up minutes on the back end, and matching up against an opponent's top line. He has 274 points in 659 career games.

Hanifin was ranked No. 2 on ESPN's NHL trade deadline board. The Boston Bruins, New Jersey Devils, Tampa Bay Lightning and Florida Panthers were among the teams that inquired about him.

The Golden Knights now boast one of the NHL's deepest defense corps. Hanifin joins a group that includes Alex Pietrangelo, Shea Theodore and Alec Martinez, all of whom were on Vegas' Stanley Cup-winning roster.

Hanifin is the second key player the Golden Knights have added ahead of Friday's NHL trade deadline. Vegas acquired Capitals winger Anthony Mantha on Tuesday, with Washington retaining 50% of his salary.

The Golden Knights were able to create more cap space ahead of the deadline by putting captain Mark Stone on long-term injured reserve. The winger suffered an upper-body injury in a Feb. 20 loss to the Nashville Predators and the team received relief on his $9.5 million cap hit.

The team has said it's unsure when Stone will return to the lineup. Stone underwent back surgery last year and missed the final three months of the regular season. He returned for Game 1 of the Golden Knights' first-round playoff series.