Gray was promoted from the practice squad by Pittsburgh on Friday.
Gray takes the roster spot cleared up by Stefen Wisniewski's placement on IR. The Steelers are missing both starting guards with David DeCastro (knee) also injured, so Gray will provide much-needed depth on the offensive line.
Pittsburgh waived Gray on Saturday, Jeremy Fowler of ESPN.com reports.
Gray was originally selected by the Steelers in the seventh round of this year's draft. Mark Kaboly of The Athletic reported Sunday that the rookie was able to find a spot on Pittsburgh's practice squad, so he'll be able to stick around in Pittsburgh and develop.