The National Hockey League free-agency period is basically a moving target.

Needs and wants for all 31 franchises change frequently as players get snapped off the market or, in the Calgary Flames’ case on Thursday, suddenly become an option.

Striking a deal with the Carolina Hurricanes, Flames GM Brad Treliving acquired goaltender Eddie Lack and defenceman Ryan Murphy along with a seventh-round draft pick in 2019 in exchange for defenceman Keegan Kanzig and a sixth-round pick in 2019.

The Hurricanes also retained 50 per cent of Lack’s salary which gives the Flames a modest US$1.375-million cap hit.

“I think it’s a big part of it,” Treliving said. “From an economic standpoint and a salary cap standpoint, that made it work. He comes in at a very manageable number, and that was certainly a big part of this equation.”

But it wasn’t all of it.

Lack, 6-foot-4 and 187 lb., is 29 years old and comes to the Flames with 136 NHL games under his belt with the Hurricanes and the Vancouver Canucks. Since ’13-14, the native of Norrtalje, Sweden, has a 54-51-18 record with a 2.56 goals-against average and a .911 save percentage along with nine shutouts.