Pruitt (knee) is not practicing Thursday, Teresa Varley of the Steelers' official site reports.
Pruitt has now missed back-to-back practices due to a knee issue, resulting in Pittsburgh's elevation of tight end Rodney Williams from the practice squad to the 53-man roster. If Pruitt isn't able to suit up Sunday versus the Chargers, Darnell Washington and Connor Heyward will figure to benefit most from increased opportunities behind Pat Freiermuth.