Rashard Mendenhall

Cardinals running back Ryan Williams underwent a platelet-rich plasma injection in his ailing right knee about 10 days ago. Williams is just one of many athletes to receive such injections, which are designed to send highly-concentrated platelets, the part of blood that helps us heal, to the injured area.

The patient’s blood is drawn and then put through a centrifuge. That concentrates it down to 7-10 times the normal amount of platelets. The substance is then injected into the injured area.

“It tricks the body into regenerating,” said Dr. Luga Podesta, an orthopedic surgeon at Kerlan-Jobe Orthopaedic Clinic in Los Angeles.

He likely won't play in the Cards next preseason game, but the story says the hope is Williams returns to activity as his body dictates. He probably wouldn’t jump back into full action, but work back gradually. The sense is his roster spot could be in jeopardy, as much as the Cards like his ability. Rookies Stepfan Taylor and Andre Ellington are next up on the depth chart should Williams not make the cut. It likely means more of a workload for Rashard Mendenhall, too.