The Steelers placed Driscoll (undisclosed) on injured reserve Monday with a designation to return, Teresa Varley of the team's official site reports.
Driscoll will now need to miss at least four games of the regular season on injured reserve before he is eligible to return to the Steelers' active roster. The offensive tackle is dealing with an unknown issue, and it is unclear if he will need more than the minimum required time to recover.