PITTSBURGH -- The Steelers are handling some personnel business before shutting things down for the regular season.

The team has restructured the contract of right tackle Marcus Gilbert, according to a source. His 2016 base salary dips from $3.95 million to $760,000, according to NFLPA records. The Steelers did this to secure about $2 million in cap space, and Gilbert still gets the difference. The Steelers often convert base salary money to a signing bonus as a way to find cap relief.

As of Thursday morning, the Steelers carried around $4 million in cap space, according to ESPN's roster management system. That's before the team signed linebacker Vince Williams to a three-year contract extension.

The Steelers face decisions on 2017 free agent guard David DeCastro and the future of Antonio Brown, who has two years left on his deal and is due $6.25 million. Gilbert's restructure is an easy thing to do and gives the team more options for the next three weeks. Running back Le'Veon Bell, wide receiver Markus Wheaton, linebacker Jarvis Jones and linebacker Lawrence Timmons are among the team's 2017 free agents.

The Steelers have a longstanding policy not to negotiate with players once the season starts, which this year is Sept. 12 on the road against the Washington Redskins.

DeCastro is a priority but a deal has been slow to develop. He's still the best bet for the Steelers' biggest signing before that September date.