On Tyrann Mathieu's starting opportunity

The Arizona Cardinals have big plans for rookie defensive back Tyrann Mathieu. They said so on draft day. They affirmed their feelings when they gave Mathieu 38 snaps, the highest total for any defensive back on the team, during their first exhibition game of 2013. They deployed Mathieu on blitzes as if coaches couldn't wait to try out a new toy.

Now, with starting safety Rashad Johnson sidelined by a sprained knee, Mathieu has a direct path into the starting lineup for the Cardinals' second exhibition game, Saturday against the Dallas Cowboys.

Might Mathieu keep the job? It's a logical question on the surface, but it could miss one of the key points with Mathieu. He was going to play extensively this season regardless, and no single position on the field was going to define his role. Mathieu will play in coverage, including against slot receivers. He'll rush the passer. He'll play free safety.

Mathieu measured just under 5-foot-9 at the NFL scouting combine. He weighed 186 pounds. That is classic slot cornerback size, not safety size, but measurables and specific positional labels do not define the Cardinals' expectations for him.

The explanation coach Bruce Arians gave on draft day remains the best one I've seen yet.

"We will probably start him at weak safety and then with our defense, with the way it’s structured, he can slide in to the slot as a free safety, so basically playing with three corners but one of them is also a safety," Arians said then. "He gives that flexibility where we wouldn't have to substitute."

The Cardinals' starting secondary played just 17 snaps in the exhibition opener. Mathieu will play with that group against Dallas. Might the coaching staff leave him in the game for another extended run? It couldn't hurt. Mathieu has so far proven ready to handle whatever the staff has thrown his way. Arians called him the most dynamic Cardinals player in camp to this point.