Now it's the NFC's turn.
Here's a look at a handful of clubs that, despite adding talent, failed to address an Achilles' heel:
Carolina Panthers, wide receiver
Steve Smith's revival alongside quarterback Cam Newton is well-documented. But Smith turns 34 this month and Carolina has little depth at the wide receiver position beyond Brandon LaFell, an underwhelming target who makes better sense as a third option. The recently signed Ted Ginn and Domenik Hixon are patches. With a rare talent like Newton running the show, the Panthers' failure to surround him with more dynamic pass-catchers is baffling.
Atlanta Falcons, pass rusher
The Falcons did fine work upgrading their secondary by adding cornerbacks Desmond Trufant and Robert Alford in the first two rounds. But general manager Thomas Dimitroff failed to land a premier pass rusher. Fourth-rounder Malliciah Goodman is a long-armed defensive end out of Clemson, but he's little more than a rotational player out of the gate. Atlanta will struggle to put heat on quarterbacks unless 31-year-old Osi Umenyiora catches on fire.
Detroit Lions, offensive tackle
Detroit's offensive line remains a work in progress. Lions coach Jim Schwartz has confirmed that Riley Reiff will open the season as the team's starting left tackle, a role he'll need to grow into. On the right side, the Lions have issues after last year's starter, Gosder Cherilus, signed with the Indianapolis Colts. That leaves the untested Jason Fox and Corey Hilliard to battle it out. We'd be surprised if Matthew Stafford is sleeping through the night.
Minnesota Vikings, middle linebacker
The Vikings had an outstanding draft, but failed to address the middle of their defense. Moving Erin Henderson into the Mike slot is far from ideal for Minnesota. It pulls the longtime outside 'backer out of his natural position and puts pressure on rookie Gerald Hodges to produce in his place. The Vikings haven't ruled out bringing Brian Urlacher into the fold, but Minnesota would have done well to find a long-term solution of their own. Seventh-rounder Michael Mauti doesn't figure as an immediate contributor, and that's what this team needed.
Washington Redskins, offensive tackle
Robert Griffin III, like Stafford, needs better protection up front. Trent Williams was a stud at left tackle in 2012 -- voted by his peers at No. 99 on the "Top 100 Players of 2013" -- but there are plenty of questions on the right side. Tyler Polumbus figures as the starter, but he's a short-term fix who ProFootballFocus ranked 77th among 80 qualifying offensive tackles last season. Jeremy Trueblood and Tony Pashos equally are unsettling options. Run, RG3, run.
Follow Marc Sessler on Twitter @MarcSesslerNFL.