ARLINGTON, Texas -- Patrick Peterson hasn't faced a starting quarterback in the preseason.
The three-time All-Pro cornerback for the Arizona Cardinals is getting himself in regular-season form anyway.
Peterson returned an interception 30 yards for a touchdown after Dallas decided to sit quarterback Dak Prescott and running back Ezekiel Elliott in what was supposed to be the dress rehearsal, and the Cardinals rolled to a 27-3 exhibition victory over the Cowboys on Sunday night.
The Cardinals (3-0) forced eight turnovers to give them 16 takeaways in the preseason. That included two muffed punts by Dallas (0-3), the second recovered for a touchdown by Trent Sherfield to open the scoring in the first quarter.
Prescott's absence made it three straight weeks that Arizona didn't face the opposing starter. San Diego's Philip Rivers skipped the opener, and Drew Breessat for New Orleans last week.
Sam Bradford led two largely ineffective series for the Cardinals after completing all seven of his passes in the first two preseason games. He was 1 of 4 for 6 yards as Arizona generated just one first down.
Josh Rosen, the 10th overall pick and likely backup to Bradford in the regular season, didn't play after injuring the thumb on his throwing (right) hand in practice last week.
The Cowboys were missing center Travis Frederick and right guard Zack Martin, part of the reason Prescott didn't play. The other reason was a longer-than-planned touchdown drive of 16 plays on Prescott's final possession of the second preseason game against Cincinnati.
Owner Jerry Jones said last week he didn't need to see Elliott, the 2016 NFL rushing leader as a rookie, in a preseason game. It figures to be the first time in three seasons that Elliott, who is healthy, will miss the entire preseason since starters are generally expected to sit in the finales.
Peterson stepped in front of Cooper Rush's pass to Tavon Austin along the sideline and held the ball in the air most of the way on the easy stroll to the end zone. Rush, who won the backup job as a rookie with a strong preseason last year, was 11 of 17 for 93 yards with two interceptions.
Peterson also forced a fumble by toppling Rod Smith when the running back tried to hurdle him. Smith was originally ruled down, but replay showed the ball coming out before his arm hit the ground. The Cardinals intercepted three passes and recovered three fumbles, not counting the muffed punts.
Dallas defensive end Randy Gregory had another milestone in his return after missing last season on a substance-abuse suspension. Gregory, who made his preseason debut last week, easily beat starting left tackle D.J. Humphries with a spin move to sack Bradford on Arizona's third offensive play.
ANOTHER MISSING STAR
Like Elliott, Arizona running back David Johnson didn't play, likely signaling the end of his preseason at eight carries for 50 yards with a touchdown. Chase Edmonds had 55 yards on 11 carries. T.J. Logan, a fifth-round pick last year before spending the entire season on injured reserve, ran 59 yards for a touchdown in the third quarter.
MOMENT OF SILENCE
A moment of silence was held before the national anthem for the late Sen. John McCain, with his hometown Cardinals on the sideline. Receiver Larry Fitzgeraldlooked up to see the image of McCain on the huge video board hanging over the center of the field, and the crowd cheered afterward. McCain died Saturday.
Cardinals: RB D.J. Foster, listed third in the depth chart, injured a knee during a touchback on a kickoff and didn't return.
Cowboys: Already thin at safety, Dallas lost Kavon Frazier to a left shoulder injury in the first quarter. He was starting in place of Xavier Woods, who injured a hamstring last week against Cincinnati.
There were no apparent protests during the pregame playing of "The Star-Spangled Banner."
Preseason finales for both teams Thursday night: Cowboys at Houston; Cardinals at home against Denver.