The defense comes in ranked 23rd by Pro Football Focus, and 18th at Football Outsiders. But as the PFF article notes, injuries to key players (Nick Perry, Mike Daniels, Morgan Burnett) have held them back. Daniels and Perry played the past couple weeks, but while Daniels is not currently listed on the injury report and he hasn't since duplicated his Week 1 dominance against the Seahawks. Perry has been playing with a cast after hand surgery and he hasn't been as effective since his return, being one-handed. Burnett is still currently out of practice dealing with an injured hamstring.The PFF data says the Minnesota Vikings have the league's best defense: https://t.co/rtnHec5d1u— Sam Monson (@PFF_Sam) October 19, 2017
Even at 100%, the defense has been limited by a lack of playmaking in the secondary and not much from either of their star edge rushers (though Perry's got a good excuse). Free agent OLB Ahmed Brooks hasn't made much of a difference yet (currently limited by a back injury). Though LB Blake Martinez has been outstanding at times, and so has rookie S Josh Jones. Their injuries at cornerback were ridiculous against the Vikings, though House, King and Randall all seem currently on track to play next Sunday against the Saints. They'll probably still be without Burnett, and even with their cornerbacks potentially returning, they'll need more from their safeties than they've been providing.
Meanwhile, the usually awful Saints defense has been much better this season, currently they're ranked ahead of the Packers by both PFF and Football Outsiders, in large part thanks to rookie CB Marshon Lattimore. It's not exactly a big test for Hundley, the Saints still have issues on defense and they'll be playing them at Lambeau, but it won't look good if he struggles at home with a week to prepare against a mid-tier defense, plus he gets back his starting tackles (both currently limited in practice).