CALGARY — General manager Brad Treliving didn't wait until the start of unrestricted free agency to fill the Calgary Flames' needs.

The most aggressive GM in the NHL in recent days kept up his torrid transaction pace Friday by re-signing defenceman Michael Stone to a three-year contract extension worth $10.5 million.

Stone, 27, opted out of the UFA market opening Saturday to remain with the Flames. Calgary had acquired him from the Arizona Coyotes just prior to the February trade deadline.

"A goal right when I got traded here was to stay in Calgary and not only for the fact that we're close to family," said Stone, whose wife is a Calgarian.

"But it's a really good hockey club. That's something I haven't been part of a whole lot."

Treliving's multiple moves over the last two weeks built some cost certainty ahead of free agency that helped retain Stone and strengthen an already deep defensive corps.

A relatively economical goaltending package — the trades for Mike Smith and Eddie Lack involved the other team eating a portion of their salaries — was significant for the GM given the Ottawa Senators re-signed backup Mike Condon for an annual cap hit of $2.4 million.

The Arizona Coyotes retaining 25 per cent of Smith's cap hit and the Carolina Hurricanes agreeing to cover half of Lack's gave the Flames experienced goaltending without having to break the bank for it.

Smith, 35, will cost the Flames $4.25 million annually for the next two years according to CapFriendly.com. Lack, 29, has a year left on his deal that counts $1.375 million against the cap for Calgary.

"A big part of that deal is the retention with Eddie," Treliving said Friday at Scotiabank Saddledome prior to the Stone announcement. "There was a lot of activity in the goaltender market. You get a sense of where prices might be going.

"Putting both goalies together at the number we put in, it worked for us economically."

Treliving's body of work over the last two weeks also includes spending next year's first- and second-round draft picks to get defenceman Travis Hamonic from the New York Islanders, re-signing winger Kris Versteeg to a one-year deal and convincing coveted college forward Spencer Foo to commit to a contract that becomes official Saturday.

In addition to draft picks for Hamonic, the cost to the Flames was defensive prospects Brandon Hickey and Keegan Kanzig, downgrading from a second-rounder to a fourth-rounder in 2019 or 2020 and dropping from the sixth to the seventh round in the 2019 draft.

"We've chosen this far to go the trade route in terms of addressing some of our needs," Treliving said. "We'll see what the next little bit brings from free agency. The gun goes off tomorrow, but we've got a long time until October.

"Some of the things we've done gives us a little time to step back and maybe see how the market plays out, whether it be the next couple days or the next few weeks and months."

Calgary put 24-year-old defenceman Ryan Murphy, who came in the Lack deal, and six-year Flames winger Lance Bouma on waivers Friday with the intent of buying out their contracts.

Hamonic, Stone, captain Mark Giordano, T.J. Brodie and Dougie Hamilton make for an enviable group of defencemen in Calgary.

The Flames now owe Arizona a fifth-round draft pick in 2018 in addition to the third-rounder they initially gave up for Stone.

The six-foot-three, 210-pound defenceman from Winnipeg had two goals and four assists and was plus-5 in 19 games. Stone scored once in four playoff games.

Treliving managed to woo Foo, an Edmonton native whose hometown has a new arena, to Calgary where the Flames seem capable of a longer playoff run than they had this season.

Calgary (45-33-4) had one of the best records in the NHL after Nov. 15 (40-23-3), but was swept in the first round by the Anaheim Ducks.

"People look at our team right now and think there's a chance to have success," Treliving said. "This is all on paper. We haven't done anything yet.

"Let's keep it in proper perspective. The calls are encouraging in people thinking there's a chance to have a good team here in Calgary."