Dennard, who was making his first NFL start for the injured Adam Jones, injured his right shoulder while tackling Arizona's John Brown on an 18-yard touchdown reception in the Cardinals' 34-31 victory at University of Phoenix Stadium.
Rookie fourth-round pick Josh Shaw replaced Dennard and played 18 snaps. Chris Lewis-Harris also saw action on seven snaps.
If Dennard's shoulder injury is season-ending, he will be the first Bengals player placed on Injured Reserve since the season began.
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