Three things: Cardinals-Raiders

Three things to watch for Friday night in the Arizona Cardinals' third exhibition game, this one against Oakland at University of Phoenix Stadium (10 p.m. ET kickoff):

1. Ticking QB clock. Kevin Kolb and John Skelton have another opportunity to provide evidence of their worthiness as starting quarterbacks. Kolb in particular needs a boost after two forgettable performances in the preseason. Kolb appears to be suffering from the same problems that held him back last season: pressing too hard, bailing from the pocket too quickly, getting off rhythm, not trusting his secondary receivers. Kolb in June: "Sometimes when you want something really bad, you press a little bit too hard. I'm trying to make sure that doesn't happen. I'm trying to make sure I stay relaxed, stay calm, because when I play like that, I usually play pretty good football. ... Hopefully try to make that last for 16 weeks."

2. RB health. Second-year running back Ryan Williams could make his 2012 preseason debut 364 days after tearing a patella. Getting Williams through the game healthy is a top priority. Any sort of setback would raise fears for the Cardinals, who are counting on Williams and starter Beanie Wells to bounce back from knee surgeries. Neither played in the first two exhibition games. LaRod Stephens-Howling has missed practices recently with a groin injury, further depleting the ranks at running back. Williams carried four times for 21 yards against Oakland in the Cardinals' 2011 exhibition opener. He suffered the knee injury on his first carry the following week.

3. Outside pass-rush. Outside linebacker Quentin Groves has a chance to emerge as a contributor in Arizona after unproductive stops in Jacksonville and Oakland. Groves, 28, has generally outpaced modest expectations recently. He had four tackles, including two for losses, during the exhibition opener. He made a special-teams tackle at Kansas City last week. There could be earlier opportunities to rush the passer against the Raiders if a knee injury keeps out starter O'Brien Schofield. Groves, a second-round choice in 2008, was a rookie when he brought down Green Bay Packers quarterback Aaron Rodgers for an 11-yard sack on a third-and-8 play. That was the last time Groves sacked a quarterback during a regular-season game.