(Sports Network) - It's been a long time since the Buffalo Bills and Arizona Cardinals were relevant on the NFL scene, but both teams have designs on ending their long-suffering ways this season.

These two clubs fostering high expectations will square off this Sunday at University of Phoenix Stadium, where the Bills put their unbeaten record on the line against an Arizona squad that's eager to be back home.

As one of only two clubs that have gotten off to a 4-0 start, Buffalo has emerged as one of the major early surprises of the 2008 season and appears poised to end a nine-year postseason drought. The Bills, who have recorded only one winning campaign (a 9-7 mark in 2004) since last reaching the playoffs in 1999, have not started out a year with five straight wins since 1991.

Buffalo hasn't won five consecutive games at any point since the club ripped off six victories in a row late in the 2004 season.

The Bills have built their impressive current mark on the strength of a sturdy defense and extremely heady quarterback play from second-year pro Trent Edwards. Both were instrumental in Buffalo's 31-14 decision over the wayward St. Louis Rams last Sunday, a game in which the Bills rallied from a 14-6 halftime deficit by scoring 25 unanswered points after intermission.

Buffalo took a 20-14 lead on cornerback Jabari Greer's 33-yard interception return for a touchdown early in the fourth quarter, and Edwards later put the finishing touches on the triumph with a well-thrown 39-yard scoring pass to top receiver Lee Evans.

The Cardinals, who last made the postseason in 1998, seized early front-runner status in the wide-open NFC West with a pair of wins to begin the season. However, the momentum from that excellent start has since been quashed by back-to-back losses to Washington and the New York Jets during an extended stay on the East Coast.

Arizona looked like a road-weary team during last weekend's wild 56-35 setback to Brett Favre and the Jets, with the Cardinals committing a whopping seven turnovers and falling behind 34-0 at the half. Six of those miscues were attributed to quarterback Kurt Warner, whose prolific 472-yard passing performance was neutralized by three interceptions and a trio of lost fumbles.

A return to the cozy surroundings of University of Phoenix Stadium may do the Cardinals some good. Arizona has won its last four home tests, including a 31-10 throttling of Miami back in Week 2, and is 7-2 as the host since the start of the 2007 season.

SERIES HISTORY

Buffalo has a 5-3 lead in the all-time series with Arizona, winning four consecutive games against the Cardinals dating back to 1986. The Bills won the most recent head-to-head meeting, 38-14, at Ralph Wilson Stadium in 2004. Buffalo last visited Arizona in 1999, claiming a 31-21 decision in Sun Devil Stadium. That marks the only head-to-head meeting between the clubs in Arizona. The last win over Buffalo for the Cardinals franchise came in 1984, when the team resided in St. Louis.

Bills head coach Dick Jauron is 2-0 in his career against the Cardinals, with both of those meetings dating to his tenure with the Bears (1999-2003). The Cardinals' Ken Whisenhunt will be meeting both Jauron and Chicago for the first time as a head coach.

WHEN THE BILLS HAVE THE BALL

The continued progress made by Edwards (930 passing yards, 4 TD) has made the Bills an increasingly dangerous passing team, something that couldn't be said during last year's 7-9 season. The sophomore signal-caller has completed better than 65 percent of his passes and thrown just two interceptions through the first four games and has effectively directed an aerial attack that's producing nearly 220 yards per game (12th overall). Evans (14 receptions, 332 yards, 1 TD), who's averaging 23.7 yards per catch so far, is the game- breaking deep threat among the wideout corps, while the sure-handed Josh Reed (17 receptions) serves as the possession target. Edwards won't have his primary slot receiver available for a second straight week, however, as Roscoe Parrish (7 receptions, 1 TD) will miss a few more games while recovering from recent thumb surgery. Talented rookie James Hardy (2 receptions, 1 TD) has a golden opportunity to showcase his skills with Parrish sidelined, but the second-round pick has yet to make an impact.

Arizona's pass defense acquitted itself well when facing questionable competition during its two season-opening wins, but the secondary has shown some chinks in the armor as of late. After surrendering two second-half touchdowns through the air in their Week 3 loss to Washington, the Cardinals were torched for 284 net passing yards and a whopping six touchdowns by Favre in Sunday's rout by the Jets. The absence of standout safety Adrian Wilson (13 tackles, 1 INT) clearly coincided with the defense's shoddy showing last week, and it's unclear as to whether he'll be able to return from a hamstring strain in time for this game. Arizona was also missing its leading sacker in end Bertrand Berry (7 tackles, 3 sacks), who definitely won't play on Sunday due to a groin tear. That should be good news for Edwards, who was taken to the turf four times by the Rams in Week 4. For the year, Arizona ranks 16th in the league in passing yards allowed (204.5 ypg).

Not having Wilson in tow didn't have as great an effect on the Cardinals' rushing defense, as replacement Aaron Francisco (17 tackles) made nine stops last week and the team limited the Jets' Thomas Jones to 46 yards on 18 attempts. Arizona has been generally solid defending the run all year long, and could better its No. 14 overall rating in that category (101.3 ypg) with Sunday's expected return of nose tackle Gabe Watson, who's been out since the preseason with a knee injury. Karlos Dansby (29 tackles, 1 sack) and Gerald Hayes (28 tackles) are the club's top two tacklers who form one of the league's more underrated inside linebacker duos.

While Buffalo has made noticeable strides in throwing the football compared to a year ago, the team's running game can be labeled a mild disappointment so far. The offensive line hasn't consistently opened holes for highly-skilled running back Marshawn Lynch (275 rushing yards, 4 TD, 12 receptions), as the 2007 first-round choice is averaging a pedestrian 3.5 yards per rush and hasn't totaled more than 83 rushing yards in a game this year. Lynch and third-down specialist Fred Jackson (118 rushing yards, 1 TD, 11 receptions) have been assets as receivers, with the pair having combined for 23 catches and 174 yards over the first four games. Jackson had a key 22-yard touchdown run during last week's comeback against St. Louis.

WHEN THE CARDINALS HAVE THE BALL

Arizona boasts the NFL's fourth-ranked passing attack (290.8 ypg) and showed off its quick-strike ability on offense during the second half of its loss to the Jets. The Cardinals scored touchdowns on their first five possessions after intermission to give the Meadowlands fans a few anxious moments, with Warner (1222 passing yards, 8 TD, 4 INT) amassing the second-highest yardage total of his outstanding career. The two-time league MVP remains a deadly accurate and strong-armed passer at age 37, but last week's six-turnover outing also illustrated his vulnerability when given inadequate protection. Warner was sacked five times and fumbled on four occasions, while New York's consistent pressure had a big hand in the veteran quarterback's three picks. The Cardinals' terrific receiver tandem will be short a man on Sunday after two-time Pro Bowler Anquan Boldin (27 receptions, 366 yards, 5 TD) suffered a fractured sinus membrane as the result of a violent helmet-to-helmet collision with the Jets' Eric Smith. Return specialist Steve Breaston (13 receptions), who posted career bests of nine catches and 122 yards a week ago, will take Boldin's place opposite playmaker extraordinaire Larry Fitzgerald (24 receptions, 415 yards, 2 TD). All three wideouts finished with over 100 yards last week.

Buffalo's Cover 2 scheme has allowed a scant 168.5 passing yards per game in the early going, but the secondary will be without top cornerback Terrence McGee (14 tackles, 2 INT, 5 PD) after he sprained his left knee in last week's win. Third-year pro Ashton Youboty (16 tackles, 1 sack) will instead start opposite Greer (10 tackles, 1 INT, 4 PD), with rookie first-round pick Leodis McKelvin (2 tackles) taking over Youboty's usual nickel role. Speedy end Aaron Schobel (15 tackles, 1 sack), who's delivered double-digit sack totals in three of the previous five seasons, will be in charge of applying heat to Warner, while three-time All-Pro tackle Marcus Stroud (15 tackles, 2 sacks) is a proven disrupter along the interior. The Bills have recorded a very respectable 10 sacks through four games.

Stroud, acquired in a trade with Jacksonville during the offseason, has also helped upgrade a run defense that was a real problem area for Buffalo in 2007. The healthy return of young middle linebacker Paul Posluszny (26 tackles, 3 PD), who had his rookie season cut short by a broken arm last September, has been a boost as well to a defense that is surrendering a decent 112 rushing yards per week (17th overall). Buffalo did permit 167 yards on the ground to St. Louis last Sunday, but just 19 of that total came after halftime.

Running the ball has not been Arizona's speciality so far this season, as the team's meager 3.2 yards per carry average is the worst in the NFL. The front wall's subpar play has been one reason for that unwanted figure, as is the continued decline of running back Edgerrin James (277 rushing yards, 2 TD, 8 receptions). The 10th-year vet has been gradually losing touches to rookie Tim Hightower (73 rushing yards, 3 TD, 8 receptions), who's impressed in short- yardage situations as well as a receiver.

FANTASY FOCUS

Warner probably had his owners both jumping jubilantly off their sofas and pulling out their hair with his roller-coaster performance last week, but he's still a worthy No. 1 fantasy quarterback who figures to be chucking the ball around frequently on Sunday. Although his numbers could take a slight dip with Boldin sidelined, you shouldn't have any reservations about starting Warner this week. Using Fitzgerald in your lineup is a no-brainer, and Breaston should make a nice waiver pickup for those with their best wide receivers on byes. Stay away from using James, whose value has tumbled with the rookie Hightower's emergence as the vulture back. On the Buffalo side, Lynch may not have given his possessors the yardage totals they were anticipating after likely making him a first-round pick, but the impact back has scored four touchdowns in four games and should be used without hesitation. Evans is an every-week play as well, while Edwards makes for a potentially attractive option for those in need of a bye-week fill-in. Finally, start the Buffalo defense if you've got it. The Jets showed a week ago that the opportunity for points exists in a matchup with Arizona's high-powered but mistake-prone offense.

OVERALL ANALYSIS

A strong case can be made for either team in this evenly-matched interconference matchup. Buffalo's 4-0 start cannot be dismissed, but a recent narrow win over a dysfunctional Oakland club and last week's brief struggle with the awful Rams may reveal that this is a team that's not completely ready for the big stage. The Bills have defended the pass quite well through the season's first quarter, but they also haven't faced a team that throws the football remotely as well as the Cardinals, who have their share of red flags as well. Arizona can't run the ball worth a lick and could be entering Sunday's tilt without arguably their best offensive and defensive players. This battle could very well be decided by special teams and the kicking game, two areas where the Bills often excel. Look for Buffalo's unheralded defense to come up with one big play that will keep its unforeseen unbeaten streak intact.

Sports Network Predicted Outcome: Bills 20, Cardinals 17