Essex will sign a two-year, $1.92 million deal that includes a $500,000 signing bonus, the source indicated.
By getting a two-year commitment from Essex, the Steelers can try now work on getting long-term deals done with tackles Max Starks and Willie Colon. Left tackle Marvel Smith has been looking around with other teams.
Essex was a third-round pick of the Steelers in 2005. He has played in 31 games and has four starts.
John Clayton is a senior NFL writer for ESPN.com.