Dolphins at Cardinals -- Week 4

Where: University of Phoenix Stadium, Glendale, Ariz. (indoor)

When: Sunday, 4:05 p.m. ET (CBS)

Spread: Cardinals by 5.5

2012 records: Dolphins (1-2, AFC East: 0-1); Cardinals (3-0, NFC West: 1-0)

Past results: Two most recent meetings -- Sept. 14, 2008: Cardinals 31, Dolphins 10; November 7, 2004: Cardinals 24, Dolphins 23. Series record: Dolphins lead 8-2.

What matters: If Arizona defensive players were brimming with any more confidence, they'd be dancing on the field. This unit is good, and it knows it. And if there was any need for proof, just look for Michael Vick, probably somewhere buried around the 42-yard line, flat on his back. The Cardinals punished Vick and the Eagles offensive line, and now they welcome a rookie quarterback and a running game that features a banged-up Reggie Bush.

Who matters: Ryan Williams, it's on you. You too, William Powell. With Beanie Wells on injured reserve with turf toe and LaRod Stephens-Howling sidelined by a hip flexor, the Cardinals' running game is going to rely on Williams and William almost exclusively. Is Williams up to the task? He was against the Eagles, coming up with big plays in the fourth quarter and atoning for his late-game fumble against New England. Meanwhile, the Dolphins' backfield is hobbled, too, as Bush suffered a knee injury against the Jets in a 23-20 loss. 

Key matchups: At a certain point, you might end up feeling sorry for Ryan Tannehill on Sunday. He's a rookie, on the road, facing a defense that has allowed the second-fewest points and has racked up the second-most sacks. Not an easy task for a youngster. And he's no Michael Vick.

Injuries of note: Tight end Todd Heap (knee) is expected to miss a second-straight game, while defensive tackle Darnell Dockett (hamstring) is also listed as doubtful. Safety Adrian Wilson (groin) and quarterback John Skelton (ankle), meanwhile, are listed as questionable. 

Inside stuff: The loss of Dockett could be a big one for a Cardinals defense that thrives on its depth. Luckily for Arizona, Calais Campbell and Dan Williams are playing at peak strength. The Cardinals have had great push up front, particularly when it matters most, and that's freed linebackers Paris Lenon and Daryl Washington.

Stat you should know: When Larry Fitzgerald is on, he's one of the best receivers of all time. When he's on against a depleted defensive backfield? Uh-oh. Fitzgerald is coming off NFC Offensive Player of the Week honors for his 114-yard, nine-reception, one-touchdown performance against Philadelphia, and now he faces a Dolphins team that has struggled against the pass.

Looking ahead: This is the first of four very winnable games for an Arizona team that has won nine of 11 and three straight to open the season, leaving them one of only three undefeated teams. St. Louis, Buffalo and Minnesota are in the offing before a big matchup with division-rival San Francisco.

Prediction: Cardinals 24, Dolphins 17

For more news and analysis from Cardinals blogger Jon Gold, follow @CBSSportsNFLARI on Twitter.