Harrison has missed both of the Steelers (1-1) games this season as he continues to recover from arthroscopic surgery he had on Aug. 15. He practiced prior to their Week 1 game at Denver, but said his knee swelled up, and he's been out ever since.
Polamalu missed Pittsburgh's Week 2 win with a calf injury he sustained against Denver.
Without them, the Steelers limited the Jets offensively, but allowed 4.1 yards a carry. The defense will again give Ryan Mundy the start - he started alongside Ryan Clark in Week 2, and replaced Clark in Week 1.
Judging by the play on the field, the Steelers may opt to start Jason Worilds in Harrison's place over Chris Carter. Worilds and Carter split snaps in Week 2, and Worilds - who missed all of the preseason with a wrist injury - was used sparingly in Week 1.