Freiermuth (concussion) didn't participate in Thursday's practice session, Teresa Varley of the Steelers' official site reports.
Freiermuth remains in the league's concussion protocol after exiting Sunday's win over the Titans, and he was unable to practice for a second straight day. If he's unavailable for Sunday's Week 16 matchup against Kansas City, Zach Gentry and Kevin Rader would be in line for additional work.