Cardinals center Johnson out for year with knee injury

TEMPE, Ariz. -- The Arizona Cardinals placed center Al Johnson on injured reserve Saturday, sidelining him for the season.

Johnson hurt his knee in training camp and had surgery in early August. Coach Ken Whisenhunt had said he hoped to have him back in the lineup on opening day.

Johnson missed two games last year with a knee injury.

Replacing the 29-year-old Johnson on the roster was center Pat Ross, who was elevated from the practice squad. Ross was claimed by the Cardinals on waivers from Carolina on August 1. He spent training camp with the team and was released last Saturday and re-signed to the practice squad on Monday.

The Cardinals also released safety Oliver Celestin.