Updated

The operative number for Sunday's Arizona-Buffalo game is 31.

Arizona's 31st-ranked offense (out of 32 teams) faces Buffalo's 31st-ranked defense. Call it the resistible force meets the movable object.

The Cardinals are averaging 273.2 yards per game. They have not topped 300 in a game yet this season. Buffalo has given up an average 449.4 yards per game. In the last two, the Bills have allowed a mind-boggling 1,201 yards in the last two games, the most in consecutive weeks since the New York Yanks surrendered 1,227 in 1950.

The Cardinals (4-1), tied with San Francisco for the NFC West lead despite their offensive woes, have had extra time to shake off their brutal 17-3 loss at St. Louis two Thursday nights ago. The Bills (2-3) stayed out West after their humbling 45-3 loss in San Francisco, practicing at Arizona State to avoid a second round trip across the continent.

Maybe the desert sun will soak out the shock of what was supposed to be a respectable defense crumbling in the last six quarters. After taking a 21-7 lead over New England early in the third quarter two weeks ago, the Bills have been outscored 90-10

"Your soul is hurt. You hurt in your heart. You hurt in your brain," Buffalo coach Chan Gailey said. "You hurt everywhere when you do not play well. If you are any kind of competitor you are hurt. You want to go out and rectify it."

The pain of the Cardinals lies along the embattled offensive line and in battered quarterback Kevin Kolb, who has been sacked 17 times in the last two games, nine by the Rams. Against St. Louis, the Cardinals scored their fewest points in eight seasons, but Kolb insisted the offense was close on a number of plays.

"Whether it was me or somebody else or it's just one guy here and there, it was a handful of them," he said. "If we just hit on half on them, which we've been doing, the game's a totally different ball game. But that's why it's the NFL. It's not always going to be perfect."

Arizona's running game, already one of the worst in the NFL, took another blow when running back Ryan Williams hurt his left shoulder against St. Louis and had season-ending surgery. With Beanie Wells already sidelined for at least five games, that leaves the duties to LaRod Stephens-Howling, William Powell and Alfonso Smith. Stephens-Howling is the only one of the three with significant playing experience, and he missed the last two games with a hip injury. He is expected back against Buffalo.

They operate behind a shaky offensive line, with tackles D'Anthony Batiste and rookie Bobby Massie beaten repeatedly on the edge. With Levi Smith out for the season and no one added to the roster, the only options are to provide help from the tight end or backs or to simply get improved play along the line.

"D'Anthony Batiste and Bobby Massie are NFL players," offensive line coach Russ Grimm. "They have to step up."

The Bills are a banged-up bunch, especially along the offensive line. Adding to their woes was the loss of defensive end Mark Anderson with a left knee injury. Anderson and defensive end Mario Williams were big-money additions in the offseason, one reason the play of the defense is so disappointing.

Williams, slowed by a wrist injury, has 13 tackles in five games, nine solo.

The Bills see this weekend as a chance for defensive redemption — if the players take personal responsibility, defensive tackle Kyle Williams said.

"The main thing is you cannot say if the D-line had been better, if the linebackers had done better, if safeties or the offense had done better," Williams said. "The main thing is everybody on this team, especially on defense, has to look in the mirror and say 'OK, what can I do better?'"

The Cardinals are no doubt happy to be home, where they have won eight in a row, one shy of the franchise record. Expect it to be close, though, because five of those victories have come in overtime.

Lost in all the Arizona offense vs. Buffalo defense talk is the matchup of the Bills' offense against the Cardinals' defense.

While the Cardinals are depending on little-known, inexperienced players at running back, Buffalo brings a strong 1-2 running punch in Fred Jackson and C.J. Spiller.

"They've got two good running backs, one speed, one power, two great receivers and a good tight end," Arizona inside linebacker Daryl Washington said.. "We can't underestimate them. We're at home. They're needing a win, anxious for a win. We're coming off a loss as well, so we've got to come in with the mindset that we need a win. It's very crucial for us."

Arizona's speedy, aggressive defense has been susceptible to big plays the past two games. Still, the Cardinals held Rams quarterback Sam Bradford to a 7-for-21 day for 141 yards. Arizona had not allowed more than 21 points in a game this season.

Buffalo quarterback Ryan Fitzpatrick has spent the week near his old backyard. He grew up in nearby Gilbert and was a fan of Arizona State and the Cardinals.

"This is a really cool week for me," he said, "being able to be here, growing up around here and growing up a Cardinals fan. It is cool for me to be here and being able to spend a little bit of time with my family during the season. This game will mean a lot to me. Obviously it will mean even more if we come out on top."

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Online: http://pro32.ap.org/poll and http://twitter.com/AP_NFL

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