TEMPE, Ariz. -- Bruce Arians has been critical of himself recently for abandoning the run too quickly.

He now has more motivation to stick with it.

When the Arizona Cardinals traded for Adrian Peterson on Tuesday, they acquired the type of back Arians needs to keep running the football, whether it's behind a beat-up offensive line or not, trailing or not.

With Peterson, Arians said he'll stick with the run longer.

"Yeah, probably," Arians said. "I think that's a fair assessment. We need to do that anyway. But we'll also have our passing game ready to roll."

Peterson's impact on the offense should be felt immediately Sunday. He'll be the starter. He'll be the feature back. He'll be the running game -- and it can use the help.

Arizona is last in the league in total rushing yards (259), rushing yards per carry (2.59) and rushing yards per game (51.8). No team has finished the season averaging fewer than 66.4 yards per game since the merger, according to ESPN Stats & Information. The last time a team averaged fewer than 60 rushing yards per game was the 1946 Lions.

"I haven't been satisfied with our running game," Arians said. "No knock on Chris Johnson. I love Chris Johnson. It just didn’t work out. When [Peterson] was available, we thought it was the best thing for our football team."

And Peterson thinks he can help.

He also knows the Cardinals are looking to him for help.

"I would expect they're expecting a lot from me," Peterson said. "And that's OK."

By sticking with the run, thus sticking with Peterson, the Cardinals will have an opportunity to balance out their offense. It's been off-kilter through five games. They've attempted passes on 71.1 percent of their offensive plays and ran on 28.9 percent.

Quarterback Carson Palmer would like to see, ideally, a 50-50 split, or, at most, a 60-40 divide. Peterson agrees.

"That's the only thing I'm coming in here thinking about is changing that so we can present to a defense a more balanced offense, an offense that can run the ball and pass the ball, as well," Peterson said. "We can't look at, get caught up in the past. It's all about what you're going to do going forward. So that's what I'm focusing on."

Adding Peterson to the offense brings an "extra dimension" to the Cardinals, Palmer said.

"He can run away from defenders, he can run through defenders, he runs violently, he runs behind his pads," Palmer said. "He's a threat, obviously. He's been a threat since his first day in this league.

"I think the big picture is that he's a guy that can rip one off and run away from defensive backs and he can run through defensive backs."

That's the plan for Peterson.

He can be a key weapon for the Cardinals to keep defenses, especially their pass rushes, honest, Palmer said. Getting Peterson the ball early in games would be important to help establish a rushing presence, which has eluded Arizona thus far this season.

"Getting him downhill, even when it's just coming to the line of scrimmage, it may not be a 10-yard run, but a big guy like that, putting his body on a corner that's having to come up and make tackles -- getting him going early would be great," Palmer said.

But it'll only happen if Arizona's offensive line can open holes.

Arians hopes the likely return of left tackle D.J. Humphries and left guard Alex Boone will contribute to an improved performance by the offensive line, which Arians feels can create more opportunities for the backfield.

It's not something that Peterson is concerned about, however. He's watched tape on Arizona's offensive line and sees fight in the line, which he likes.

"It's not my first rodeo," he said. "I've been in situations where I didn't have the best offensive line in front of me and was able to be productive and accomplish some great things as a team and individually, as well.

"Guys are out there working hard."

Peterson said he tends to be hard on his teammates, pushing them, trying to motivate them. He said he expects the same from them.

Before Sunday, however, Peterson will approach this week as a student.

He needs to learn his role, the playbook and the scheme. He stayed up until 3 a.m. Wednesday studying the playbook, and expects to keep his study habits going all week. The terminology is different, he said.

Running the ball is "pretty much easy," Peterson said. He knows his A gap and B gap, six hole and nine hole.

The hardest part of Peterson's transition to a new offense will be learning the pass protection and his routes. Arians said the Cardinals' scheme for running backs is "not very complicated." Peterson won't play on third down, Arians said.

Arizona will throw as much at Peterson as he can handle. He might not get it all this week or next week, but he'll be around for the long haul, able to soak it in for however long it takes.

"I feel in any system, it's being on the same page with the offensive line, knowing your assignments, knowing the route you have, what protections, making sure you're keeping that quarterback upright," Peterson said. "That's going to be the toughest challenge for me."