The Steelers today came to a contract agreement with another free agent, Justin Hartwig, with the idea he will become their starting center.

Hartwig agreed to a two-year contract for almost $4 million, according to ESPN. He was released by the Carolina Panthers, where he was working on a five-year, $17 million contract.

Last year, the Steelers' biggest signing in free agency was center Sean Mahan of Tampa Bay. Mahan, like Hartwig, also can play guard and may either compete with Chris Kemoeatu at that position or become the swing man as a backup to both guard and center.