TEMPE, Ariz. (AP) The Arizona Cardinals running game, so critical to their big-play offense, will be in the hands of a rookie in the divisional playoff game against the Green Bay Packers on Saturday night.
His coaches and teammates are confident David Johnson can handle it. So is he.
''With Carson (Palmer) playing, I don't have any more rookie nerves,'' Johnson said after practice Wednesday.
Not that he shows his nerves anyway.
''I'm a pretty calm guy, a pretty mellow guy,'' Johnson said, ''don't get too excited or too out of the box.''
He certainly has excited Arizona fans, especially since he took over as starting running back a month ago.
In his five starts, he has rushed for 442 yards, with another 216 yards receiving. Those 658 yards from scrimmage are more than any other player in the NFL in that span.
Johnson rushed for 99 yards at St. Louis in his first start, 92 in his second against Minnesota and a breakout 187 at Philadelphia the following week. Johnson leads the team with 13 touchdowns.
''He's played well. Hopefully, he continues to,'' offensive coordinator Harold Goodwin said. ''The kid is humble. The kid works his butt off and he's smart, so he's got a bright future ahead. Hopefully, he can protect the ball like he's been doing and we should be all right.''
Johnson, a third-round draft pick from Northern Iowa, made a big impression from the start. The first pass Palmer threw to him in the opener against New Orleans went 55 yards for a touchdown. The next week, at Chicago, he returned the opening kickoff 108 yards for a score.
But he didn't play much in the backfield until Chris Johnson went down with a knee injury at San Francisco on Nov. 29. Andre Ellington also was hurt at the time, so the job went to David. He's played so well that, without a doubt, it's his to keep.
He said it was his second start when he shook off the nerves for good.
''I started getting calm,'' he said, ''and once I started letting the game come to me, once I started getting a little more comfortable in the offense, I think I had more confidence in myself that I can do stuff that I do on the field.''
Palmer has said Johnson is far more mature than the average rookie.
He'd better be, because running the ball is crucial to set up the play-action passes far downfield that have become Arizona's trademark.
And Ellington, whose speed and ability to catch the ball make him a big-play threat, is healthy enough to play and spell Johnson.
Palmer said the advantages of an effective running game are ''countless.'' Among them, running out the clock, which allows the defense to rest, and putting the team in manageable short-yardage situations.
''It's great to be in third and three, and the team doesn't know if it's a pass or a run,'' Palmer said, ''where a lot of teams, you get in third and three and it's a pass because the running attack isn't as aggressive as we are. So, it's endless.''
Many players hit what's known as ''the rookie wall'' in the long NFL season.
But that didn't happen to Johnson.
''Since I didn't play a whole lot at the beginning, I didn't really have a chance to hit the rookie wall,'' he said. ''I'm feeling great. My body's ready to go.''
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