It's no secret that quarterbacks on the move will put stress on a defense, but the Cardinals have been particularly haunted by it in 2017.
While Matthew Stafford isn't known for his mobility, a 15-yard scramble on third down and a six-yard touchdown pass on a broken play kept the Lions close while they were discombobulated early in Week 1.
Then on Monday, Cowboys quarterback Dak Prescott completed 3-of-5 passes for 107 yards outside of the pocket, including a 37-yard touchdown and a 53-yard gain to Brice Butler. In his 15 other passes, Prescott managed only 76 passing yards.
"It's very tough (to stop), because in our defense, we know nine times out of 10, we're not going to have safety help," cornerback Patrick Peterson said. "When we're breaking on their initial route, obviously we don't know what the quarterback's doing. The receiver knows exactly what the quarterback is doing, because he's breaking, and now he has his eyes back on the quarterback."
On the touchdown pass, cornerback Justin Bethel stuck closely to Butler, but couldn't recover as the wide receiver shot vertically toward the end zone after ending his initial route.
"I just wish we could have that play over." Peterson said. "Justin was in great position, but when he broke contain, Dak made a hell of a throw."
Peterson said it's something the secondary has been playing close attention to this week, as it's going to come up several more times this season. The Cardinals – who did do an excellent job keeping Jacoby Brissett neutralized -- have games left against Russell Wilson, Deshaun Watson and Marcus Mariota.