Steelers using free agency to protect Ben Roethlisberger

The signing of Ryan Harris provides valuable experience and swing-tackle help for an already solid offensive line that's all in on protecting Ben Roethlisberger.

What's clear: The left tackle job is Alejandro Villanueva's to lose now. Harris can start, but won't unless Villanueva -- the 6-foot-9 project who acquitted himself well in 11 starts a year ago -- drops the ball in training camp.

Kelvin Beachum wanted to resume his place as an NFL starter and the Steelers weren't willing to pay him starting-left-tackle money. That's probably why Russell Okung isn't in Pittsburgh. He got an offer from the team Sunday, but it wasn't enough. Okung's a starter.

The team had the Villanueva card in their back pocket throughout free agency, allowing them to bargain-shop.

The price tag on Harris ($4 million over two years, per the Denver Post) agrees with this assertion.

The Steelers are smart to strengthen the line with Harris and the re-signing of guard Ramon Foster. The Steelers have given offensive line coach Mike Munchak plenty of options. This is a line that allowed 20 Roethlisberger sacks in 12 starts, the best clip of his career. Mike Adams, a former second-round pick who battled injuries, might be No. 8 on the overall offensive-line depth chart.

As for defense, the Steelers can continue rebuilding it through the draft, though don't be surprised if they sign Lions defensive end Jason Jones.