There's an increasing need for NFL defenses to stay on top of heavy passing offenses that employ single back sets.
The Green Bay Packers, among others, are known to run a lot of 3WR, 1TE 1RB (known as "Posse") sets. Teams can struggle to defend this offense in a base package, so they can remove a linebacker and bring on another defensive back - their nickel package.
But teams like the Packers show they can run out of this formation if that nickel package is too pass defense-oriented.
The Steelers utilized what they called their "Big Nickel" package last year, setting four players on the line with two linebackers and five defensive backs. This can help counter a run-oriented Posse package.
Adding in a team's ability to utilize a bigger, more physical tight end is still a concern as well. Teams - particularly the Giants in 2012 - used different nickel backs, including a safety instead of a traditional cornerback.
The Steelers drafted Shamarko Thomas out of Syracuse with the idea of keeping that physical run-stopping presence on the field but still being flexible enough to cover seam-running tight ends.
What Thomas lacks in size he makes up for in strength. The Post-Standard did a piece on Thomas in April highlighting his work ethic and desire simply to get on the field.
While the Steelers spent an unexpected amount on free agent CB William Gay, presumably to come in and fill the nickel back role, it wouldn't be surprising, as the Steelers full team minicamp gets underway Tuesday, to learn of them working on another variation to their nickel package that involves the liberal use of a safety in the slot.
Perhaps that will be Thomas. It could be second-year S Robert Golden. However they divvy it up, it's another wrinkle Dick LeBeau is likely to have been forging in the lab this offseason.