Gilbert is, however, probable to return to the field on Thursday night.
The Steelers, down 13-10 on the road at the time, already lost starting Pro Bowl center Maurkice Pouncey on the offensive line in the first quarter.
Mike Adams, a rookie second-round pick out of Ohio State, filled in for Gilbert at tackle.
Gilbert is a two-year NFL veteran who was drafted by the Steelers in the second round of the 2011 NFL Draft out of the University of Florida. In his rookie season with Pittsburgh, Gilbert won the Joe Greene Great Performance Award, which is given out yearly by the team to the organization's top rookie.
Steelers quarterback Ben Roethlisberger has been both sacked and hit once so far Thursday night as the game approaches halftime.