New Orleans Saints linebacker Jonathan Vilma is having knee surgery Thursday in Philadelphia, according to ESPN’s Adam Schefter.

Schefter tweeted that Vilma will be out for the remainder of the preseason but is expected back for the Saints opener against the Atlanta Falcons on Sept. 8 in the Mercedes-Benz Superdome. The procedure is meant to relieve swelling and discomfort Vilma has been feeling.

Vilma has been in and out of training camp sessions with an undisclosed injury since Aug. 5, and he missed the Aug. 9 preseason opener against the Kansas City Chiefs. Inside linebacker David Hawthorne has been lining up with the first-team defense whenever Vilma has been unavailable.

Another inside linebacker the Saints have at their immediate disposal is Ramon Humber, who’s been backing up starter Curtis Lofton.

Vilma, 31, spent time last year on the physically unable to perform list as he recovered from offseason surgery on his left knee. While appealing a season-long suspension given to him in the wake of the bounty scandal, a punishment that was ultimately vacated, Vilma started 10 games for the Saints, getting a combined 49 tackles, one sack, one interception and a touchdown.

Vilma has a history of knee problems. The New York Jets traded him to the Saints after he sustained a season-ending knee injury in 2007.

Meanwhile, Hawthorne, who came to the Saints last year after four seasons in Seattle, missed five games for New Orleans in 2012 with an injured hamstring. He finished last season with a total of 43 tackles.

Humber appeared in 13 games for the Saints in 2012, mostly on special teams. He had 14 coverage stops, tied for second on the team.

Vilma last met with the news media on Tuesday. Asked about the success the defense had in certain situations at training camp and during the 17-13 preseason win against the Chiefs, he said, “We like the fact that we’re being coached to do (things for games) and what we’re executing on the field and practice is correlating to the game.

“Granted, it was only one preseason game and they didn’t have their whole offense in and we didn’t have our whole defense in, but the fact that we can just take the coaching from the meeting rooms, to the practice field, and to the games and have them translate is encouraging.”

Coach Sean Payton declined to discuss the status of Vilma after the linebacker missed practice Wednesday. The Saints on Thursday morning had not made any announcements about Vilma.

Vilma is among several important Saints defenders who have missed practice with injuries as the Saints install new defensive coordinator Rob Ryan’s 3-4 scheme. Martez Wilson hurt his elbow July 29 and returned to practice in a limited capacity Aug. 13.

Junior Galette hurt his left leg Aug. 7 and had not returned to practice as of Wednesday.

Wilson and Galette are candidates to fill in for Victor Butler, who was projected to start at strongside outside linebacker but will miss the season after tearing an ACL during organized team activities in June.

Furthermore, Kenyon Coleman, projected to start at left defensive end, tore a pectoral muscle on Aug. 6 and is out for the season as well.

The Saints will wrap up their three-week training camp with a practice Thursday afternoon, which is closed to the public. Check back for more Saints information on later today and in tomorrow’s edition of The Advocate.