Understand, this is bigger than defensive coordinator Monte Kiffin. Or defensive line coach Rod Marinelli.
Seemingly every time something goes wrong with a team folks want to fire the coach. Sometimes, that's the right move. Not always.
Last year, we blamed defensive coordinator Rob Ryan for the Cowboys' defensive woes. Now, we're blaming Kiffin.
It's the players.
It doesn't matter whether we're talking about 3-4 defense or the 4-3. And it doesn't matter whether the scheme is simplistic or complicated. If a team doesn't have enough good players -- not players with good reputations -- then it doesn't matter.
These Cowboys don't have enough good players on defense. One day, perhaps, they will.
Sport is fluid. Guys improve. The defense we saw pillaged in the second half against the San Diego Chargers and for four quarters against Denver might evolve into a good unit.
Right now, it's not.
Look at the numbers. Be warned, though, they're rated "M" for mature.
In the past six quarters, the Cowboys defense has yielded nine touchdowns and three field goals. It has allowed 777 yards on 107 plays, an average of 7.2 yards per snap.
"There was a relentless nature to how we played," Garrett said. "What's this guy talking about? They gave up 500 yards and 51 points. When you watch the tape, we played better in that regard than we had the previous week."
After five games, the Cowboys rank 28th in total defense (409.2 yards) and 31st in pass defense (326.4 yards). Teams have converted 40.3 percent (25 of 62) third-down plays against Dallas and it ranks 31st in first-down defense (7.22 yards).
That's important because it prevents the Cowboys from putting teams in long yardage situations on second and third down, where the pass rush doesn't have to worry about the run.
"You try to evaluate what we're doing as coaches, what we're asking our players to do," Garrett said, "and how they're doing it and if we're asking right guys to do what they're capable of doing."
The Tampa 2 defensive scheme, we've been told by Garrett and others, is all about the front four generating a fierce pass rush. Then seven defenders can drop into coverage.
All of that sounded great in the spring, when the projected starters were Anthony Spencer (32.5 sacks), Jay Ratliff (27), DeMarcus Ware (111) and Jason Hatcher (16), because they had combined for 186.5 career sacks.
They have a combined three NFL sacks.
Hatcher and Ware have combined for seven sacks this season, but Hatcher is getting double-teamed regularly and Ware's body already is breaking down. He's playing through a pinched nerve and a back strain.
"You have to live in reality that these are the guys we have," Garrett said. "We feel good about these backup players who have come in and emerged as starters and guys we've gotten off the streets that have emerged as backup contributors for us."
As you know, there won't be a Bob Lilly walking through a Valley Ranch door. Or a Randy White. Or a Harvey Martin.
The Cowboys already have yielded 400 yards passing to four quarterbacks in the first five games, and they still must play Washington's Robert Griffin III twice, Detroit's Matthew Stafford, New Orleans' Drew Brees, the New York Giants' Eli Manning, Chicago's Jay Cutler and Green Bay's Aaron Rodgers.
Would you really be surprised if they gave up four more 400-yard passing days this season?
The Tampa 2 scheme is designed to prevent pass plays of 20 yards or more, but Denver's Peyton Manning and San Diego's Philip Rivers attacked the space in front of the linebackers as they dropped into their zones and let their running backs and tight ends run after the catch.
Each passed for more than 400 yards.
When the Cowboys linebackers moved up to challenge the tight ends and running backs, Manning and Rivers exploited mismatches and attacked deep. Especially Manning, who had 14 completions of 14 yards or more.
"We didn't make enough plays to get him out of rhythm," Garrett said of Manning. "It starts up front; we didn't affect him enough with our guys. We didn't cover them on the back end."
They didn't even make the Broncos punt. The Cowboys scored 48 points and still found a way to lose.
Guess what? It could happen again.