The Sports Xchange

TEMPE, Ariz. — Depth at running back for the Arizona Cardinals was a concern in preseason as back after back seemed to be limping with a hamstring injury.

That’s why the team signed Chris Johnson midway through camp. And then he injured his hamstring a couple of days later.

That depth will be tested now.

Starter Andre Ellington likely will miss one to three weeks with a mild sprain of a knee ligament.

Johnson is healthy now, so he is likely to start against the Bears. Rookie David Johnson will be the backup, and Stepfan Taylor will be third.

“Chris will be the starter,” Head coach Bruce Arians said. “Everybody just bumps up a spot. Both those guys (Johnson and Johnson) can pick up that slack easily.”

The Cardinals were relieved with the news on Ellington. They hope to use him more judiciously this year, because they felt he wore down a year ago. Ellington played with a partially torn foot tendon a year ago, then went on injured reserve in December with a core muscle injury.

He put his big-play ability on display against the Saints, rushing for 69 yards on 12 carries. He nearly broke a couple of those runs for bigger gains.

“I thought we left some plays on the field,” Arians said. “We missed some holes. We had a couple of blocks that if we finished a little bit better, we would have had even bigger runs. Andre was very explosive. Chris was decisive.”

–The Cardinals are 9-1 in home openers at University of Phoenix Stadium, including six consecutive victories. They are 14-3 at home under head coach Bruce Arians, and they now are 17-4 against non-division foes in Arians’ three seasons. That includes an 11-0 mark at home.

REPORT CARD VS. SAINTS

PASSING OFFENSE: A — Carson Palmer wasn’t sacked and he passed for 307 yards and three touchdowns. Tight end Darren Fells had two big catches, including a 17-yard touchdown. Larry Fitzgerald became more involved in the second half and finished with six catches for 87 yards.

RUSHING OFFENSE: A — After averaging just 3.2 yards a carry in 2014, the Cardinals opened the season with 20 yards on 25 attempts (a 4.8-yard average). Andre Ellington and Chris Johnson had some nice holes to run through.

PASS DEFENSE: C — The Cardinals shut down the Saints’ receivers, but New Orleans’ running backs gained 149 yards receiving. The Cardinals gave up big plays against screens and simple flare patterns.

RUSH DEFENSE: A — The Saints gained only 54 yards on 20 carries. Their longest run was nine yards. Inside linebacker Kevin Minter and safety Tony Jefferson did a solid job against the run.

SPECIAL TEAMS: C — Too often, the Cardinals had trouble getting the right number of men on the field. A penalty in the second quarter kept a Saints drive alive, and they scored their only touchdown. Kicker Chandler Catanzaro made all four of his extra points and his only field goal. Drew Butler overcame a poor first punt and was excellent the rest of the game.

COACHING: B — Aside from the substitution issues on special teams and the passes to the running backs, there were no issues. Head coach Bruce Arians proved again that he’s a bold play-caller, calling for a short pass to running back David Johnson on second down with 1:44 left. Johnson was wide open and scored from 55 yards out.