TEMPE, Ariz. — The Arizona Cardinals have been able to prosper despite numerous injuries because they have a strong belief in themselves.

The roots of that belief run all the way to Seattle. It was the Cardinals’ upset of the Seahawks in Seattle last December that laid the foundation for what the team is accomplishing this year.

“We had four turnovers and our defense played outstanding,” coach Bruce Arians said of that 17-10 victory in Week 16. “But we hung in there and made a play offensively to win it. To go up there and do it – we had been so close a number of times. The belief system that everything we’re doing is working solidified itself up there last year.”

This year, the teams have reversed roles. At 9-1, the Cardinals have a three-game lead over Seattle (6-4) and San Francisco in the NFC West. Seattle needs a victory to stay in the division race and to boost its chances of a playoff berth.

The Cardinals are entering the most difficult part of their schedule. Four of their remaining six games are against division foes, including two games against the Seahawks.

“Hard as hell,” Arians said of the next six games. “Everybody’s in it. (Atlanta is tied for first in the NFC South). The Rams are still technically in it. Kansas City’s in first place, so everybody that we play right now is do or die. It’s extremely difficult.”

The Cardinals might have to play Seattle without receiver Larry Fitzgerald, who suffered a grade 2 sprain of his left knee against Detroit. Fitzgerald, who hasn’t missed a game since 2007, is optimistic he can play, as is Arians.

But a grade two sprain is no minor injury, and it can keep some players out two to four weeks.

Fitzgerald was injured just before halftime Sunday, but he returned in the second half and caught a key third-down pass to help preserve Arizona’s 14-6 win over the Detroit Lions.

Fitzgerald caught two passes for 33 yards Sunday and has 46 catches for 658 yards and two touchdowns this season.

MEDICAL WATCH: TE Troy Niklas is out for the season after suffering an ankle injury against the Lions. Niklas missed three games with a high ankle sprain earlier this year and aggravated the same ankle last Sunday. With Niklas out, Darren Fells moves up to the No. 3 spot behind John Carlson and Rob Housler. Niklas, a second-round pick, was just beginning to display some solid blocking skills, which the Cardinals need, given their struggles in the run game. … OLB Matt Shaughnessy, who is on the reserved/designated to return list, can begin practicing this Wednesday. He is eligible to play against the Chiefs on Dec. 7.

REPORT CARD VS. LIONS

PASSING OFFENSE: B – Quarterback Drew Stanton started quickly in his return to the starting job, passing for two touchdowns in the first quarter. But he also had two passes intercepted in the second quarter and failed to lead the offense to any more scoring opportunities. Stanton was not sacked.

RUSHING OFFENSE: F – The Cardinals gained 46 yards on 26 carries, a 1.8-yard average. The Lions were first against the rush so the struggles were expected.

PASS DEFENSE: A – The Cardinals stuck with their dime package most of the game and they gave the Lions troubles. They were able to get pressure with only four or five rushers, and the secondary clamped down on the Lions’ two biggest threats: Calvin Johnson and Golden Tate. Tate had two catches for 41 yards, and Johnson had five for 59.

RUSH DEFENSE: C – The Rams rushed for 98 yards on 19 carries, a 5.2-yard average. Joique Bell gained 85 yards on 14 carries, with a long of 33.

SPECIAL TEAMS: B – Nothing flashy but all units turned in solid efforts. Drew Butler’s put two punts deep in Lions territory in the fourth quarter.

COACHING: A – The Lions passing game was thwarted for much of the day. The Cardinals played to their strength, depth in the secondary, by using dime packages for most of the day. Coach Bruce Arians called a conservative game after Drew Stanton had two passes intercepted in the first half. It made sense, with an eight-point lead and a defense that was playing well.