GLENDALE — Two seasons ago, Ryan Williams’ rookie year was cut short by a devastating knee injury suffered in a preseason game against the Green Bay Packers at legendary Lambeau Field.

Friday, the Arizona Cardinals open their 2013 preseason schedule by visiting Lambeau again, but Williams won’t get the opportunity to exorcise those injury demons. The third-year running back from Virginia Tech has been sidelined during training camp with a sore knee, but is confident that this is all part of getting healthy enough to play again.

“Nothing’s wrong with my knee, it’s all healed properly,” Williams said following practice Monday afternoon. “I think it’s just part of the process. I’ve talked to a lot of people who have had this injury — Carson (Palmer) has also had this injury, Dave (Zastudil), our punter and our safety Y.B. (Yeremiah Bell) — they’ve all gone through this.

“It just sucks that I’m going through this right now and missing time, but the good sign of things is that I’m going through the healing process right now. I took a P.R.P. (platelet-rich plasma) shot and it should do what it’s supposed to do so I can be back on the field soon.”

Williams has a long history of ailments, dating back to his college days when he missed a good portion of his sophomore season with a hamstring injury. That was followed by the torn patellar tendon in his rookie season and a season-ending shoulder injury suffered in a Week 5 loss to the St. Louis Rams in 2012.

Head coach Bruce Arians said Monday morning that each moment Williams is on the sideline, the more it will be for him to make the 53-man roster out of camp.

“It’s hurting him extremely not to be on the field competing for the job because those other guys are doing so well,” Arians said.

Williams says his focus is on getting healthy, not if he’ll receive a pink slip from the organization that picked him in the second round of the 2011 NFL Draft.

“I can’t worry about things like that,” he said. “I’m very confident in what I’m able to do when I’m feeling good. I’m not worried, because once I’m on the field my play will speak for itself.”

Confidence aside, Williams won’t suit up for the Cardinals in Green Bay, but guaranteed his return soon after that.

“I know for a fact that I’ll be playing in the Cowboys game, for a fact,” Williams said. “I like to be a man of my word and I know that I’m playing the Cowboys game.”

Dallas will visit the Cardinals at University of Phoenix Stadium Saturday, August 17.

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