Mike McCarthy was an unhappy man Wednesday afternoon after leaving Ray Nitschke Field, the Green Bay Packers pre-season practice field across from Lambeau Field.

Simply, "I wasn’t very happy with the way we practiced," he told the assembled media.

Wednesday was a padded practice to simulate a Friday during the regular season as the Packers host the Seattle Seahawks in the all-important third preseason game tonight in Green Bay.

It’s the game where the starters will play more than the first two games – likely into or through the third quarter – and the first roster cut downs need to be made by Tuesday by 3 p.m.

Yet, as McCarthy said, "We didn’t take full advantage of the opportunity (Wednesday) to get ready to play."

He said it wasn’t a "good day" for plenty of players across the board, and it’s not the first time McCarthy has been unhappy with the way his unit has worked during this training camp.

That distress led to the following statement:

"It’s important for us to play well as a team. We’re going to probably have some more moving parts, as it looks, as I stand here today, than I probably thought we would’ve two or three days ago. It’s important for these individuals that have this opportunity Friday night to play against excellent competition, they need to play well. You can’t have a better opponent for preseason. We’re fortunate that way."

The Seahawks will indeed provide that test, for both sides of the ball. And while McCarthy has admitted on several occasions that he has not liked what he’s seen out of the Aaron Rodgers-led offense so far (no touchdowns in two preseason games), it’s Dom Capers’ defense that will be under the greatest microscope.

A summer-long story line for the Packers has been the work put in to defend quarterbacks like Seattle’s Russell Wilson, mobile quarterbacks who can get out of the pocket on designed runs, escape pressure and also throw with accuracy.

Until the regular season begins in San Francisco, the last – and lasting – image of Packers defenders was them picking themselves off the turf as 49ers quarterback Colin Kaepernick raced past them in the playoffs last year.

In order to better prepare for the read-option and for quarterbacks like Kaepernick in Week 1 (as well as Robert Griffin III and Michael Vick after that) Capers and his staff went on many well-documented trips to colleges around the country to learn about how it’s run, and how to defend it.

We’ll finally get our first real look at how well the defense has learned those principles, and if they can apply them at game speed.

Vince Young can’t emulate Wilson, and the quarterbacks the Arizona Cardinals and St. Louis Rams trotted out the last two weeks didn’t fit the mold, either. This is the first time this young defense will be tested.

This isn't the be-all and end-all, whether the Packers are torched or contain Wilson. But, it will be a significant indicator as to how far along the team has come. Or, how far it has to go.

While everyone loves touchdowns, and there still legitimate concerns at wide receiver with Randall Cobb and Jordy Nelson hampered by injury, tonight's game is all about the defense.