New Orleans Saints linebacker Will Smith is out for the year with a knee injury, according to Pro Football Talk.
Smith was injured during Sunday's preseason game against the Houston Texans.
The exact injury was not immediately known.
Without Smith, it will be much more difficult for first-year defensive coordinator Rob Ryan to install an effect 3-4 defense. The team is also without linebacker Victor Butler, who is on the physically unable to perform list after having offseason ACL surgery.
Smith, a first-round pick in 2004, was preparing to move from defensive end in the 4-3 alignment to outside linebacker in the 3-4.
Martez Wilson is likely the fill-in for Smith. Wilson recently returned to practice after injuring an elbow early in training camp.
Smith had 58 tackles and six sacks in 2012.