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Losing their top two quarterbacks derailed the Arizona Cardinals' 2014 season following a strong start that had them looking like Super Bowl contenders.

They've faced similar adversity this year at running back, but rookie David Johnson's emergence has helped keep the Cardinals rolling.

Arizona now must contend with the loss of Tyrann Mathieu as it looks to clinch a first-round bye with a win over the visiting Green Bay Packers on Sunday.

Carson Palmer missed 10 games with a shoulder injury and torn ACL last year, and the Cardinals were down to their third-string quarterback for the remainder of the regular season and playoffs after backup Drew Stanton suffered a knee injury.

They went 2-4 after a 9-1 start - a collapse coach Bruce Arians blamed on the devastation at the top skill positions - before losing a wild-card game at Carolina.

It appeared the Cardinals (12-2) would be scrambling at running back this season with Andre Ellington hampered by turf toe, but veteran Chris Johnson stepped up and was selected as an alternate for the Pro Bowl.

Then Johnson fractured his left tibia against San Francisco on Nov. 29, leaving the job to David Johnson, a third-round pick out of Northern Iowa. The rookie is averaging 5.4 yards per carry in his three starts and rushed for 187 yards and three touchdowns in last week's 40-17 win over Philadelphia that gave the Cardinals the NFC West title.

"Coming in, having two good running backs, I didn't know what was going to happen," Johnson said. "As the game started coming more to me and started getting more carries, it's definitely been helping out.

"Now it's on to getting ready for the Packers."

Johnson's contributions have helped keep Arizona on track despite the injuries. It has won eight in a row and will secure the NFC's second seed with a victory.

The Packers (10-4) rank 26th in the league in average yards allowed per rush at 4.45 and have given up at least 100 yards on the ground in four straight.

Having Johnson playing well to complement Palmer, a Pro Bowl selection whose 106.7 passer rating ranks second in the league despite him celebrating his 36th birthday Sunday, has given Arians freedom to run his offensive system as he'd like.

"He's worked hard his whole life," Arians added of Johnson. "He had jobs at Northern Iowa cleaning latrines and working in the cafeteria. This is a very mature young man who's paid his dues. He's not like a guy who's been given everything, highly recruited and they have a sense of entitlement. You have to be very aware of those guys."

Packers coach Mike McCarthy certainly is aware of Johnson, along with the rest of the Cardinals' weapons that have them ranked No. 1 in the league in offense with an average of 422.9 yards per game.

Green Bay clinched a playoff berth with last week's 30-20 victory at Oakland and can take the NFC North with a win and Minnesota loss to the New York Giants on Sunday night. Despite winning a third straight game, however, Aaron Rodgers wasn't pleased.

Rodgers threw for 204 yards and said the offense didn't execute very well, leading to a somber press conference that seemed strange given the victory.

McCarthy defended Rodgers and others who also weren't so chipper, explaining that the expectations are greater than with some other NFL teams. A loss this week and a Vikings victory sets up a showdown for the division title Jan. 3 in Green Bay.

"It's about winning in December," McCarthy said. "There's a reason why these kind of games usually show up on your schedule this time of year. But this is about the playoffs. We're in the playoffs now. Everybody understands what we need to do to first, win the division, and then hopefully get the highest seed (possible)."

Rodgers will be throwing against a secondary missing Mathieu, a Pro Bowl selection who was lost for the year after tearing his ACL last week. He had five interceptions and returned one for a touchdown, but the Cardinals still have Patrick Peterson to help disrupt the Packers' passing game.

Arizona ranks seventh in total defense, giving up an average of 329.6 yards.

"If there was a spot we had to lose a guy, it was probably the one spot we were deep at," Arians said of Mathieu's injury. "Nobody has played better in the league than Patrick. Nobody even throws at him. Whoever he gets is canceled out."

This will be the first meeting since Rodgers threw four touchdowns in a 31-17 win at Lambeau Field on Nov. 4, 2012.