TEMPE, Ariz. (AP) — The Arizona Cardinals expected their defense to be a strength this season. It hasn't been.

That's been particularly apparent lately. In their last six quarters, the Cardinals have allowed 66 points (and scored seven).

The problems have been many.

"Busting assignments that we've been doing for years," star cornerback Patrick Peterson said. "Just being on the same page, everybody believing in one another, just playing with that energy and passion again. That's something we were missing the last two games for sure."

Defensive coordinator James Bettcher said the biggest problems have been third downs and turnovers.

Arizona ranks next-to-last in the NFL in third-down defense, allowing opponents to convert them 47.7 percent of the time. Only Tampa Bay (48.98 percent) is worse.

No one has been as bad as the Cardinals the last three games, when opponents have converted third downs just under 62 percent of the time.

In Arizona's most recent game, a 33-0 loss to the Rams in London two Sundays ago, Los Angeles was successful in 13 of 19 third-down situations.

There's no one reason, Bettcher said.

"The biggest thing is the rush has got to work the coverage," he said, "and the coverage has to complement the rush."

In other words, pass rushers have to get to the quarterback and, if they don't, defenders have to adequately cover the receivers.

Last year, Arizona led the NFL with 48 sacks. Through seven games this year, the Cardinals are tied for 24th with 13.

Outside linebacker Chandler Jones has done his part. He leads the league with 13 tackles for loss and his eight sacks are the most among linebackers. His eight sacks are the most by any player through seven games in franchise history.

But no other Arizona player has more than one.

Takeaways have been a Cardinals strength in recent seasons, but not this year.

Arizona and Cincinnati are the only teams without a fumble recovery. The Cardinals have seven interceptions and are minus-four in turnover differential, tied for 24th in the league.

Arizona's opponents have fumbled five times but have recovered them all. The Cardinals have to just keep trying to strip the ball away, Bettcher said.

"The other thing is just collision on the ball carrier," he said. "If you go look at all the fumbles through the course of the National Football League, most cases ball carriers aren't just dropping the ball. It's contact at the point, it's knocking the ball out."

Arizona ranks 24th in the NFL in overall defense, giving up 353 yards per game. They are 14th against the run at 106 but 21st against the pass at 247.

The defense doesn't play with the swagger it has shown in previous seasons.

Peterson, who is having one of his best seasons, said the team has had a chance to look at itself during its just-completed bye week.

"You get a week off, have an opportunity to look at yourself in the mirror and you've got to be true to yourself," he said.

The Cardinals, he said, "looked at our scars, saw some of the things that are preventing us from being a dominant defense and I think hopefully we should have corrected that as men individually."

Arizona (3-4) plays at winless San Francisco on Sunday.

The game follows what has been by all accounts a spirited week of practice that included two physical workouts in pads.

"We had a great week of preparation this week," Peterson said, "probably one of the better weeks I've seen since I've been here. That doesn't mean anything if we can't put it on tape on Sunday."

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