Shazier practiced Friday on a limited basis for the second consecutive day, but will miss his third straight game as he works his way back from a sprained knee.
Shazier is expected to do more next week and he will have an extra day to get better with the Steelers hosting the Houston Texans for a "Monday Night Football" game.
With quarterback Landry Jones, guard Chris Hubbard and offensive lineman Wesley Johnson expected to join Shazier, Thomas and cornerback Ike Taylor (arm) on the seven-man inactives list, Bryant or McCullers are the most likely candidates to make the 46-man gameday roster when the Steelers play the Browns.
Neither has dressed for a game this season.
The Steelers could sign safety Ross Ventrone or rookie cornerback Shaquille Richardson from the practice squad if they want an extra defensive back for depth and special teams with Thomas and Taylor out.
But they would have to make a roster move to promote Ventrone or Richardson and risk exposing a player on their 53-man roster to waivers.
It probably makes more sense for the Steelers to dress Bryant.
Bryant has the size that the Steelers might want to take advantage of when they get in the red zone, and the 6-foot-4, 210-pounder can probably play special team in a pinch if needed.
The fourth-round pick has practiced on a regular basis since overcoming an early season shoulder injury, and offensive coordinator Todd Haley said on Thursday that he has been pleased with Bryant’s work.
"He is making progress," Haley said, "no doubt about it."