But it's also a group that has trouble concentrating throughout a game.
The Cardinals shut down Frank Gore in the season opener, but gave up an 80-yard drive in the fourth quarter. The 49ers won, 20-16.
Last week, the unit gave the Colts fits in the first quarter, as the Cardinals took a 3-0 lead. They were going in for a possible 10-0 lead when Tim Hightower lost a fumble at the 5.
Instead of stopping the Colts and retaining good field position, the Cardinals gave up a 95-yard touchdown drive.
The lack of a dominant pass rusher has hurt, but the Cardinals have enough players with enough skill to compensate.
What's really lacking with this unit is maturity, and the attention to detail. Players have taken bad pursuit angles, allowing touchdowns.
Cornerback Dominique Rodgers-Cromartie has been caught out of position a handful of times.
The offense has been sputtering, too, but the lack of consistency on defense continues to be major problem for the club.
--QB Kurt Warner will use the off week to rest a sore right shoulder. Warner suffered a stinger in his throwing shoulder in the first week but it has affected his practice regimen or performance.
--RB Tim Hightower remains the team's best all-around back, but he's going to be pushed by Beanie Wells for the No. 1 job. Hightower had a costly fumble in the loss to the Colts last week.
--RB Beanie Wells carried just twice against the Colts because the Cardinals fell behind and were forced to go with their "Texas" package in the second half. That's a spread formation where Kurt Warner calls most of his plays. Wells, a rookie, hasn't had enough work in that scheme to be effective.
--WR Larry Fitzgerald's longest catch this season is 25 yards. The Cardinals must find some way to get him the ball deep. That means better protection for Kurt Warner and a better running game to set up play action.
--WR Anquan Boldin appears to be recovered from a hamstring injury that hampered him in the opening weeks. Boldin can now explode out of routes and he should be due for some productive games.
--WR Steve Breaston appears to be recovering from a knee bruise suffered in the preseason. Breaston is a good deep threat and he is excellent at making yards after the catch.
--TE Stephen Spach hasn't been as productive as the Cardinals would have liked, especially as a blocker. He plays hard but there have been too many errors in technique.
--K Neil Rackers has done a nice job, missing on just one field goal in three games. He's also a demon on kickoff coverage, preferring to sprint downfield to make tackles.
--S Matt Ware, who plays in dime packages, didn't play the last two weeks because of a stinger in his shoulder. It's a significant loss because Ware's availability allows strong safety Adrian Wilson to play closer to the line of scrimmage in pass coverage. Coaches don't yet trust rookie Rashad Johnson to fill Ware's role in the dime.
--DE Darnell Dockett suffered a sprained right ankle against the Colts and likely won't do much in the bye week. Dockett has played well when healthy in the first three weeks and is the team's best defender.
--RB LaRod Stephens-Howling has proven to be a good special teams player. He leads the team in special teams tackles and is a solid gunner on punt coverage. Stephens-Howling is gradually working into a role as a third-down back, too.