When it comes to the NFL off season, nothing is more sacred than lists. Over at Pro Football Focus, amongst a bevy of interesting reads, they are doing positional group rankings.

For the Arizona Cardinals, they have a lot of fans at Pro Football Focus because of how good their play has been of late.

In this group of rankings you have the Arizona Cardinals as the second best group of corners in the NFL, trailing only the Denver Broncos.

2. Arizona Cardinals Top CBs: Patrick Peterson, Justin Bethel, Tyrann Mathieu Key stat: Peterson averaged 19.5 coverage snaps per reception last season. No cornerback went more snaps between allowing a reception last season than Peterson, who after a subpar 2014, was back to his imperious best in 2015. Paired with fellow LSU alum Tyrann Mathieu, the Cardinals have a devastating weapon at outside corner and in the slot to shut down a variety of opposing receivers. The sole weak spot in this trio last season was Bethel, who surrendered at least 75 yards in each of the Cardinals' final four games

What you notice the most about the Cardinals is that their top two are great, but there is either unknown or unproven past that, and on this list it is only Justin Bethel, simply because the rest of the depth presents itself as rookies.

The debate on Bethel is simple, how much room does he have to grow on last seasons work?

His athleticism and willingness has never been in question, but can he turn that around to consistent play? The Arizona Cardinals certainly believe so, surrounding Bethel with only younger, more unproven talent to compete as the number two corner spot.

Could the Cardinals faith in Bethel be too great and it cost them? Could they have an eye on a veteran towards the end of camp?