Not Kliff Kingsbury’s initiation to NFL life. Not Patrick Peterson’s absence, nor rookie Kyler Murray’s impact.

Those are all fine storylines to pay attention to this summer as the Arizona Cardinals put the pieces together under a first-year head coach and a No. 1 overall pick at quarterback. But maybe the subplot that matters most is the one that will have the biggest impact on on the field in 2019.

To NFL.com’s Gennaro Filice, the one burning question for Arizona this offseason is the offensive line. “Will the O-line get in the way of everyone’s fun?” he asks.

At OU, Murray played behind one of the nation’s best units, a quintet that had four players selected in Rounds 2-4 of this draft. Now he’s getting behind a group that ranked dead last in 2018, according to Pro Football Focus. Granted, Arizona dealt with a lot of injuries up front. And (GM Steve) Keim did sign a pair of veterans … but OG J.R. Sweezy and OT Marcus Gilbert don’t come without risk. Murray’s obviously far more elusive than Josh Rosen, but no quarterback can survive playing behind an absolute sieve.

As it stands, Sweezy, a free agent addition formerly of the Seattle Seahawks, and Gilbert, a trade pickup from the Pittsburgh Steelers, are the presumed starters along the right side of the offensive line.

Former starting right guard Justin Pugh, who dealt with multiple injuries last year, has slid to left guard in early practices, where he is in line to replace the departed Mike Iupati.

But Injuries to Pugh, Gilbert, center A.Q. Shipley and tackles D.J. Humphries and Korey Cunningham ended their 2018 seasons.

Keim addressed the offensive line woes early this offseason but wasn’t aggressive filling spots in the draft until the last two rounds, where Arizona selected Georgia center/guard Lamont Gaillard (179th overall) and Morgan State tackle Josh Miles (248th overall).

The Pugh position change, plus the health and productivity across the line are all individual question-marks. At center, Shipley could be pushed by Mason Cole, who started every game as a rookie a year ago. The depth might be solid with Cunningham, Gaillard, Miles and free agent addition Max Garcia in the mix; but Cunningham and Garcia (ACL) are coming off their own injuries, while Gaillard and Miles, especially the latter, lack experience.

All that put down on paper makes this much clear: What Kingsbury and Murray can produce under all those circumstances might say more about the offensive line than it does about their own viability in the NFL.