Yes, but that's true with any team.
The level of play likely will decline with key injuries because the replacement just isn't as good as the starter, and the chemistry with the unit is destroyed, as well.
We now have 2 replacements on the OL, and the LB group is without their leader and has 2 others dinged up. Add a replacement quarterback to the mix, and it's not surprising that the 'Boys performance suffered. Remember, these units have a fairly fragile new-found cohesion which can easily deteriorate when removing just a few key components.
Arizona matched up well, given our altered roster, and the results should not have been shocking.
We all hoped Weeden would be smarter and more accurate, and that the other subs would step up, but this is a very young team, without the established veteran core that might lend more continuity.
Regarding play-calling, Weeden wasn't given more than the coaches thought he could handle, and that simple game plan was just too predictable.