Reid and Mornhinweg also knew that their quarterback, Michael Vick, has trouble reading blitzes and sometimes makes bad decisions with the ball.
They knew that the Eagles were going into battle with a patchwork offensive line that featured center Dallas Reynolds making his second NFL appearance and first start, and underachieving veteran left tackle Demetress Bell - meaning Vick would be even more vulnerable.
They also knew the Eagles' attack was missing its most consistent receiver, Jeremy Maclin.
Still, Reid and Mornhinweg looked at the Cardinals' biggest strength on defense and decided attacking it with the weakest part of their offense would yield a favorable result. I'm not a football coach. I don't claim to know as much as Reid. But even I could see that wasn't going to work.
"We thought we had some opportunities down the field in the throwing game," Reid said. "We went in thinking we would probably protect a little better than we did and be able to exploit some of the things we felt were our strengths and that we matched up best against. It didn't happen."
How do you come to that conclusion? Looking at the status of your passing game, how do you conclude that it can exploit a defense ranked near the top of the league in pass defense and sacks?
That's not logical, but it's been par for the course for the Eagles during the Reid era.
Come hell or high water, Reid is going to throw the football.
It doesn't matter if his quarterback is Vick, Donovan McNabb, Kevin Kolb, Koy Detmer, A.J. Feeley, Jeff Garcia or Mike McMahon. It doesn't matter if his receivers are talented ones like Maclin, DeSean Jackson and Terrell Owens or just bodies like Freddie Mitchell and Todd Pinkston. It doesn't matter if his offensive line is a veteran unit or a bunch of guys strung together at the last moment. It doesn't matter if he has a feature running back like Duce Staley, Brian Westbrook or LeSean McCoy, or stiffs like Darnell Autry or Chris Warren.
Reid is committed to the passing game - even when every indication going into a game says it might not be the best idea.
The Eagles have McCoy, who is coming off a season when he finished fourth in the league with 1,309 rushing yards on 273 carries - the fewest among the league's top seven rushers. He led the league with 17 rushing touchdowns and 14 rushes of more than 20 yards. McCoy is tied for fifth with 59 rushes, but would anyone argue that he shouldn't get more?
Sometimes I think Reid and Mornhinweg just look at film of an opponent's defense over and over until they can convince themselves they've found a weakness in the pass defense that they can take advantage of.
That's the only thing that makes sense for why they did what they did against Arizona.
Vick passed 37 times behind a makeshift line. Is it any wonder the Cardinals hit him 21 times? There was no upside to having Vick pass that many times. He's not that kind of quarterback.
Vick is ranked 29th with a passer rating of 66.3. He's 25th with a completion percentage of .552.
So explain how that correlates into Vick being ranked third with 125 pass attempts. Vick has never proved that he's a good enough passer to warrant 41 attempts a game. That's just asking for trouble on all fronts. Is it any surprise Vick is tied for the league lead with six interceptions?
With Vick's history, do the Eagles truly believe that exposing him to that many hits isn't going to eventually put him on the injured list? "I'll tell you he's getting hit way too much," Reid said. "At this point, it's way too much, so that part's got to end. We've got to limit that."
The best way to limit that would be cut down on the number of times Vick is put in jeopardy, but history tells us that's not a viable consideration.
Reid said the same thing for a decade when McNabb was being used as a tackling dummy. McNabb would take his beating and then get sent back out to throw 30 to 35 times the next game.
Under Reid, Vick has averaged as many throws per game (30) as McNabb did. The difference is that McNabb completed 59.4 percent while Vick completes 55.3 percent. At his current pace, Vick would attempt 667 passes - 244 more than his career high.
There are only one or two guys I can think of who would believe Vick throwing 600 passes would be a good thing.
"Well, we've got explosive players," Reid said. "So, with that, you're going to take your shots. I mean, that's what we do. That's one of our strengths and has been over the last few years. We'll continue to do that."
Come hell or high water, no matter what makes sense.
Contact John Smallwood at email@example.com. For recent columns, go to philly.com/Smallwood.