That player is safety Landon Collins, who leads the team with 6 interceptions, 1 of which was returned for a touchdown. Many of these interceptions came from Collins simply being in the right place at the right time. Regardless, he has still proven himself to be a defensive playmaker, and a player the Cowboys must account for on each and every snap.
In the season opener, the Giants gave Dallas a glimpse of how they like to move Collins around the field, and allow him to play in different roles.
On the Cowboys first offensive possession, we see Collins matched up one on one with Jason Witten. Going against the younger defender, Witten is able to use his veteran savvy and leverage to beat Collins on a crossing route and pick up a nice gain.
As good as Witten's route is, this play could not have been completed if it wasn't for Dak Prescott's precision on the throw. As early as game one in the NFL, Dak showed us that he was ready.
On their next possession, Witten meets up with Collins once again, this time in bracket coverage. Here Landon Collins is being used in the traditional, two-deep safety role. He is responsible for his deep half of the field, and brackets over the top of Witten on this play.
Most of the time, the Cowboys will see Landon Collins either in man coverage with Witten, or playing over the top in a two-deep safety look like they do here.
Sometimes, the Giants will bring their playmaker into the box and ask him to both defend the run and get after the quarterback. Here we see him in a designed blitz, coming off the edge in attempt to get to Dak's front-side shoulder. Luckily for the Cowboys, they have Ezekiel Elliott in pass protection, who comes up and delivers a good shot to jar Collins and stop the penetration.
Much later in the game, Collins shows his ability to come upfield and make tackles similar to Cowboys safety Byron Jones. Landon Collins is at his best when he is asked to simply be free and make plays, just like he does here.
Once again lined up in the two-deep safety look, Collins reads the quick screen to Cole Beasley and immediately comes up to make the tackle. He also displays patience on the shifty Beasley, allowing himself to make the sure play instead of potentially whiffing on the tackle and allowing for extra yardage.
Simply put, Dak Prescott must be cognizant of where Landon Collins is on the field at all times. The Giants will move him around, put him in the box, and trust him to cover both Beasley and Witten one on one. Dak must identify where Collins is, recognize the match-ups he is presented with, and make the smart play on that down.
So far this season, making the smart play has been the least of the Cowboys worries. Collins may cause problems, but I expect Dak and the Cowboys to overcome.