Cardinals coach Bruce Arians during last week's game against the Saints, which was another one-score loss.

Bruce Arians doubled as an illusionist in his first four years as an NFL head coach, constantly pulling close wins out of his hat. This season, that magic touch has disappeared.

Between a 12-game interim stint in Indianapolis in 2012 and his first three years in Arizona, Arians won an incredible 23 of 28 games that were decided by one score. This season, the Cardinals are only 2-5-1 in such games.

Most coaches, no matter how successful, don't consistently excel in one-score games over long stretches, so it's not a surprise Arians' results have regressed in 2016. That's no consolation to the Cardinals, whose close-game blues have played a large role in a disappointing 5-8-1 campaign.

"That's the most frustrating thing, because those are the games we've won for the past three or four years," Arians said. "To not win them, you've got to go back and really research why."

Arians pointed to field goal misses and fumbles among the reasons for the close losses, and said there will be a full review this offseason. Defensive tackle Frostee Rucker said execution is the chief culprit, but also said luck plays a role.

"It's hard to pinpoint," Rucker said. "The ball usually rolls our way and we make a spectacular play, or it will be a mishap by the other team. This year, for some reason, it's just been us. We haven't executed the way we've wanted to. And that's all phases of the game. You've seen so many lapses in situations where we always came out on the positive side of it."

In other sports, close finishes can impact a season, but not this greatly. The Chicago Cubs, for instance, went only 22-23 in one-run games in 2016 but still led the majors with 103 wins and went on to win the World Series.

The NFL plays 146 fewer regular season games, so there isn't enough time to let the results even out.

"When you put it that way, we wish we had 18 games," Rucker said. "We wish we had a little more time to get it right. Unfortunately with the way it is, we made the bed and we've got to sleep in it."

WILDCAT SUCCESS WITH KERWYNN WILLIAMS

The Cardinals started running the Wildcat in practice earlier this season to prepare their defense for opponents who used it. However, running back Kerwynn Williams proved so effective they implemented it themselves.

The formation has added an extra wrinkle to the offense, as Williams and David Johnson are a dynamic combination in the backfield. Williams scored on a 49-yard run out of the Wildcat against the Saints and has carved out a niche on offense.

"So far it's been good for us," offensive coordinator Harold Goodwin said. "A lot of times he's just making people miss. Guys are unblocked, he's been phenomenal in that way."

"For a guy who is working hard, it's a way to reward him," Goodwin added. "It also takes some of the weight off David."

Williams didn't make the team out of training camp, but seems to have ascended to the backup running back spot ahead of Andre Ellington. While Johnson is under contract next season, Ellington, Williams, Chris Johnson and Stepfan Taylor are all impending free agents.

Williams, who has six carries for 97 yards in the past two games, could be a player the Cardinals look to re-sign.

"I never really think that far into the future, especially things I have no control over," Williams said. "I feel like, whatever you do, if you put your best foot forward, everything else tends to take care of itself."

MARCUS COOPER UNLIKELY TO PLAY IN SEATTLE

Cornerback Marcus Cooper didn't practice Thursday and his back injury is expected to keep him out of Saturday's game against the Seahawks, Arians said. Rookie Brandon Williams, who also missed practice Thursday when his back tightened up, is expected to start in Cooper's place as long as his injury is minor.

Left tackle D.J. Humphries missed all three practices this week and is still in the concussion protocol, so he seems likely to miss the game. Arians said everyone else will be available to play the Seahawks.

Wide receiver John Brown (illness) and safety Tyrann Mathieu (shoulder) were limited on Thursday.

For the Seahawks, running back C.J. Prosise (shoulder) and cornerback Richard Sherman (not injury related) didn't practice.