Peter Chiarelli has his work cut out solidifying Edmonton Oilers' blueline for 2017-18

The Edmonton Oilers’ defensive depth is about to be put to the test.
The club’s major step forward in 2016-17 was due in no small part to a rebuilt blueline corps, but that itself hinged in extraordinary good health that saw the top three defenders — Oscar Klefbom (82 GP), Andrej Sekera (80) and Adam Larsson (79) — miss just five games among them. The club was able to roll with a core group of eight defenders for most of the season, and once Darnell Nurse returned from an