Ryan Williams' knee and other Cards notes

GLENDALE, Ariz. -- Nearly two years have passed since Arizona Cardinals running back Ryan Williams suffered a torn patella tendon in his right knee.

Williams, now entering his third training camp, had an ice pack on that same knee while failing to finish practice Sunday. Williams was moving briskly with a slight limp when he headed to the locker room following practice. He did not oblige interview requests.

No big deal? Major story? It was impossible to tell, but any trouble with Williams' surgically repaired right knee is a concern for the Cardinals. Free-agent addition Rashard Mendenhall is the presumed favorite to get most of the carries this season. His history with head coach Bruce Arians is one factor. Mendenhall averaged better than 1,100 yards per season with Pittsburgh from 2009 through 2011.

The shifty Williams, a second-round pick in 2011, remains a wild card until his health stabilizes. Knee and shoulder injuries ended his first two seasons.

Floyd's day

It was odd seeing Larry Fitzgerald drop a well-placed deep ball from Carson Palmer. Not long after, second-year wideout Michael Floyd impressed with a leaping grab on a deep pass to the other side of the field. Floyd looked good in this practice. Meanwhile, tight end Rob Housler impressed by catching a touchdown pass with his left arm while safety Jonathon Amaya hung onto him.

Up close and personal

The Cardinals wearing full pads for the first time in this camp, practiced running plays from the home sideline toward midfield. Fans were seated within maybe 15 yards of the action. Reporters were standing closer than that. Arians was standing within only a few feet of the offense. One highlight: right tackle Bobby Massie planting defensive end Darnell Dockett.

Former San Francisco 49er Chilo Rachal was working at left guard while the team awaited first-round pick Jonathan Cooper's arrival after Cooper reached agreement on a contract earlier in the day.

No break-in period for Cooper

Arians said Cooper would be allowed to practice in pads right away instead of waiting til his fourth day in camp. That marks a departure from 2012, when the Seattle Seahawks violated rules by allowing Terrell Owens to wear pads during his first practice.

As a league spokesman said last summer, "Day 1 is for the physical and meetings. Day 2 and 3 the player may participate, but only in helmet and shells or a padded shirt. Day 4 and for the rest of camp is in full pads."

So, what has changed? Not the CBA, but rather the interpretation of the CBA, according to the Cardinals. The language refers to the team's first day of camp, not to the player's first day of camp.

Strange sight

That was the not-so-mobile Palmer running what appeared to be a read-option play in practice before several thousand fans at University of Phoenix Stadium. Of course, it's not really an option if everyone knows the quarterback is going to pitch the ball. That is what Palmer did. The Cardinals also had cornerback Patrick Peterson playing receiver.