In the era of football as it’s currently constructed, particularly with regard to the salary cap and contract structures, it has become virtually impossible for anybody to field a ‘complete’ team. There is going to be a weakness somewhere important, even if that weakness is in lacking quality depth, which basically always is a factor at some point during the year.
The Pittsburgh Steelers certainly are not a team without flaws, even though they have the only flawless record in the NFL at 6-0. Devin Bush’s injury saw to it that that would definitely be the case. Depth at offensive line took a hit with Zach Banner’s injury as well.