Smith's arraignment on the DUI charge as well as a charge of violating rules for driving in marked lanes was to be Tuesday, but his attorney filed the not guilty pleas to both counts Friday, the Dayton Daily News reported.
A pretrial hearing date has not been set.
Smith, 25, was arrested last week in Kettering, a Dayton suburb, after an officer observed his truck drifting between lanes, the newspaper said. Tests showed he had a blood-alcohol level of 0.152. A person is considered legally drunk at the 0.08 level.
Smith ranks third on the team in tackles with 24 and has one quarterback sack.
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