Cardinals' third-round pick Johnson eager to prove his worth

The Arizona Cardinals ranked second-to-last in rushing yards per game in 2014 (81.8), just ahead of the Oakland Raiders (77.5).

So to bolster their ground game, they selected David Johnson out of Northern Iowa, where he set a number of school records, including career rushing yards (4,862), career rushing touchdowns (49) and career all-purpose yards (6,854).

"I'm going into camp in great condition physically, as good of condition as I've probably ever been in my life. I'm physically and mentally ready for the challenge that lies ahead,'' Johnson said, via WCFCourier.com. "I'm giving this everything I have.''

Johnson was able to get first-team reps during OTAs, in part due to injuries to Stepfan Taylor and Kerwynn Williams. The Cardinals' No. 1 back, Andre Ellington, battled a foot injury throughout the 2014 season and averaged just 3.3 yards per carry. He also dealt with a hip injury and underwent a sports hernia surgery. However, Ellington is expected to be the lead back and have the same role as last season, per Arians.

But Johnson should provide some help and give Arizona another threat out of the backfield, something that was noticeably missing at times from the Cardinals' offense in 2014.

(h/t WCFCourier.com)