Besides Wallace, the Steelers have a number of other starters on the free agent market.
William Gay is an unrestricted free agent, and Pittsburgh may consider bringing him back at a low cost. That would eat up valuable cap space.
The rest could go to restricted free agents Doug Legursky, Ramon Foster and Keenan Lewis, who all received the lowest tender meaning that a team would have to compensate the draft pick in the round that each player was drafted.
Neither Legursky or Foster were drafted, meaning there is no risk for any team signing them to an offer sheet, besides the Steelers having an opportunity to match.
Both players have started in a Super Bowl and, while they're not outstanding, are serviceable.
Lergusky could start in some places around the NFL and is a valuable backup, while Foster is a developing lineman who is not great, but is developing nicely and provides power on the right side of the line.
Pittsburgh needs some insurance just in case either of these players gets an offer.
The same can be said for Lewis, who carries a third-round compensation.
Lewis could step into the starting role if Gay leaves and may be due for a contract extension as well. He would be a relatively cheap option for the Steelers to start opposite of Ike Taylor.