The Pro Bowl player joined linebackers Lawrence Timmons and LaMarr Woodley and cornerback Ike Taylor in restructuring his contract to make sure the perennial AFC contenders get under the cap by March 13.
The Steelers saved $8 million in cap space by restructuring Roethlisberger's deal, a league source told ESPN NFL Insider Adam Schefter.
Pittsburgh was an estimated $8 million over the cap before reworking Roethlisberger's contract Thursday and will have to trim even more space in order to use the franchise tag on wide receiver Mike Wallace.
This is the second time in six months Roethlisberger has reworked the eight-year, $102 million deal he signed in 2008. The new contract doesn't affect the money or length of the deal but gives the Steelers some much needed cap relief.
Roethlisberger was scheduled to make $11.6 million in 2012 but the new deal will save the Steelers several million next season.
The team hopes to use some of the money freed up by restructuring to address the contract status of Wallace, who will be a restricted free agent.
General manager Kevin Colbert said Thursday in Indianapolis that he believes Wallace, elected this past season to his first Pro Bowl, will remain with the team.
"We want Mike to finish his career with the Steelers," Colbert said, "and I'm confident Mike wants to finish his career with the Steelers."
Information from ESPN NFL Insider Adam Schefter and The Associated Press was used in this report.