In quotes provided by the Saints, Brees says he sees a lot of potential in the Chiefs' defense:
I see a defense with a lot of young talent that's played really well at times and it's a 3-4 scheme, something we don't see all the time. They have some pretty talented pass rushers, some talented linebackers and some good athletes on the back end, so you see guys around that are playmakers and just knowing that you have to be aware of where some of these guys are at all times.
Maybe Brees has only watched his own team's defense as a comparison. The Saints and Chiefs are tied for dead last in the NFL through two weeks in points-per-game allowed (37.5). The Chiefs have allowed 377.5 yards per game (11th worst in the league), while the Saints are last in the NFL in that category at 461 yards allowed per game.