Alzner's had a negative impact on the possession numbers of all 11 Caps he's played 600+ mins with over the last three seasons. pic.twitter.com/WhaI25P8Rz — Todd Cordell (@ToddCordell) May 29, 2017

It's no secret the Calgary Flames would like to add another top-4 defenseman this off-season.Michael Stone was serviceable in that role, however, the Flames need to upgrade and find a legitimate partner for T.J. Brodie on the second unit if they want to become true contenders.One name I've seen thrown around quite a bit is Karl Alzner which, on the surface, makes some sense.Alzner has averaged ~20 minutes a night for the powerhouse Washington Capitals throughout his career and appears likely to hit the open market. Adding a defenseman in free agency, rather than before the expansion draft, would make things less complicated, too.In saying that, Alzner seems like an obvious candidate for overpayment in free agency and is a guy I'd stay away from.His career high in goals is five, his career high in points is 21 and he has been a big anchor when it comes to driving possession.Alzner doesn't have much foot speed, either, and that will only get worse as he ages. Basically, he is this year's Troy Brouwer.While Alzner's perceived value seems to be fairly high, the numbers suggest he's not much more than a glorified third pairing defenseman.Given the soon to be 29-year-old will almost certainly get a significant raise on the $2.8 million he was making on his last deal, I think the Flames would be much better off looking elsewhere.