LATROBE, Pa. -- No wonder why Mike Tomlin was running his cornerbacks through individual drills Saturday, a responsibility usually designated for a position coach.

Tomlin knows this year's playoff run is largely about how the secondary responds to last year's 27th-ranked passing defense. That's why the Pittsburgh Steelers trading a conditional 2016 fifth-round pick for Eagles corner Brandon Boykin is a worthwhile investment.

Even if Boykin helps a little bit, this is a success. Boykin is good value for a fifth-round pick. That pick can turn into a fourth-rounder based on playing time, but if Boykin plays significant snaps and plays well, that hardly matters.

Boykin enters his contract year having never gotten to start as an outside corner in Philly's defense despite his desire to do so. You think he'll be motivated to show out in Pittsburgh?

The Steelers likely won't promise Boykin anything, but all three current starters -- William Gay in the slot, Cortez Allen and Antwon Blake on the outside -- are put on notice. No job should feel safe.

The Steelers' corners have shown glimpses of steady play in camp. Allen, recovering from a disastrous 2014 season that included a benching, has played Antonio Brown well at times and had a red zone interception on Day 2. For some reason, Blake stood out more in offseason workouts than he has thus far in training camp. He hasn't played poorly, but the raw playmaking hasn't been there. Gay is a good veteran option but hardly a star.

This is all about competition, and the Steelers don't make this trade if they don't feel Boykin has at least a reasonable chance to earn the outside job. Absolute worst case, there's another good slot corner on the roster. Chip Kelly didn't unload Boykin because he played poorly, but after signing Byron Maxwell to a mega-deal and drafting two corners, Kelly had the positioning to get value for Boykin.

The real question mark becomes Steelers second-round pick Senquez Golson, who hasn't practiced yet while nursing a shoulder injury. I wonder how much of this move is sparked by his absence from camp. If Golson returns strong, the Steelers have potentially five corners you can roll out there and feel pretty good about -- not stars, but reliable players.

Boykin might have the most upside of everyone, which is another reason to make this move.