Pittsburgh Steelers first-round pick Derrick Harmon was carted off the field during Thursday's preseason game against the Carolina Panthers after sustaining a knee sprain. Harmon is expected to be out for about a month, according to NFL Media, which makes him a candidate to begin the season on injured reserve.

Pittsburgh Steelers first-round rookie Derrick Harmon is expected to miss several weeks following an MRI on his knee.

PITTSBURGH -- The Pittsburgh Steelers got a promising update on Derrick Harmon Saturday, and the rookie defensive tackle may only miss one game. Harmon suffered the injury on the play before his last play, which was the James Pierre interception.