Steelers coach Mike Tomlin told reporters that Harrison will be out "a number of weeks," during his weekly press conference todfay.
Meanwhile, defensive end Aaron Smith has a sprained foot and could miss the Steelers' next game against the Tennessee Titans. Plus, outside linebacker Jason Worilds has a strained quadriceps.
The Steelers are encouraged by quarterback Ben Roethlisberger. His sprained left foot isn't expected to sideline him this week.
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