New Orleans Saints linebacker Will Smith exited the field under his own power after suffering what appeared to be a leg injury during Sunday’s preseason contest against the Houston Texans. While the ailment didn’t seem to be extremely significant, Pro Football Talk has reported that Smith will miss the remainder of the season due to the knee injury.

Smith has since told reporters that he suffered a torn ACL, an injury that will require season-ending surgery to repair. Dr. James Andrews will conduct the operation.

This represents just another blow to the Saints as they attempt to move from a 4-3 to a 3-4 scheme under new defensive coordinator Rob Ryan. Prior to Smith’s injury, New Orleans had already lost outside linebacker Victor Butler and defensive end Kenyon Coleman to what are likely to be season-ending injuries. Beyond that, NFL.com points out that Jonathan Vilma is recovering from arthroscopic knee surgery, and it’s unclear what he’ll be able to provide.

To help fill in for Smith and the team’s other injuries, the Saints quickly responded to the news by acquiring outside linebacker Parys Haralson from the San Francisco 49ers. Haralson missed the entire 2012 season with a triceps tear, causing him to fall on the 49ers’ depth chart. He was a candidate to be cut, but he should be useful for the Saints considering their onslaught of injuries.