METAIRIE, La. (AP) - Jonathan Casillas was a week away from winning a starting linebacker spot for the Saints last season when a foot injury in the final preseason game put him out for the year.

Casillas is back, healthy and working vigorously through training camp, but senses that the rotation at linebacker is more uncertain than it was a year ago because of moves the Saints made to build depth in that area.

It's a good group, man,'' Casillas said after practice Wednesday night.Every position has a solid backup and even a solid backup after the backup. I think that's pretty rare, even in the NFL with the experience and talent in the league.

``They're working us in, kind of interchanging parts a little bit, trying to figure out that chemistry. I think we're trying to play with the pieces a little bit to get the best guys out there for each individual package we have.''

It appears the only linebacker job that is secure is that of defensive captain Jonathan Vilma in the middle. He has hardly missed a snap the past three seasons.

There's less certainty at both outside spots, as well as at the second middle linebacker spot when the Saints switch from their regular 4-3 alignment to the 3-4 that defensive coordinator Gregg Williams likes to use as a change of pace.

In free agency, the Saints brought back Scott Shanle, who has started at weak side linebacker the past five seasons. But Shanle could lose that job to Casillas, who was the front-runner at that spot during the 2010 preseason before his injury.

The Saints had flirted with moving Shanle to the strong side during Casillas' emergence last summer, but that doesn't appear to be in the plans this season.

Danny Clark and Jo-Lonn Dunbar shared strong side snaps in 2010, but the Saints decided on Wednesday to cut Clark, a 12-year veteran, which for the time being narrows competition between free-agent acquisitions Will Herring and Clint Ingram.

We have more depth, we have experience and we have some young guys,'' head coach Sean Payton said.When I talk about experience, you're looking at Will Herring ... I consider Casillas and obviously Shanle to be experienced players. Clint Ingram is healthy and a much different player than he was a year ago. Plus, we have the younger guys that are competing in there. So it gives us some versatility. It will be an important evaluation for us as we get into these games.''

The Saints open their preseason schedule Friday night against San Francisco.

Ingram was signed by the Saints last season but never recovered enough from knee surgery to play before being released. The Saints then brought the sixth-year pro and former Jacksonville regular back to camp this season and have begun giving him some practice snaps with the first team.

Dunbar, meanwhile, also returned in free agency and is now working either as Vilma's backup in the middle or a second middle linebacker in the 3-4 formation.

There's definitely lot of guys at linebacker who can play and I think we finally got the right pieces,'' said Dunbar, who joined the team as an undrafted rookie in 2008.We're progressing. We look good as a linebacker corps.''

Also in the mix are 2011 third-round draft pick Martez Wilson and seventh-rounder Nate Bussey, who played together last season at Illinois. The 6-foot-4, 252-pound Wilson is competing on the strong side, while the 6-foot-2, 220-pound Bussey has been working on the weak side.

The Saints continue to have high hopes for Casillas after he came so close to securing a starting role in only his second season after joining the Saints as an undrafted free agent out of Wisconsin in 2009. Williams said he just needs to stay healthy or play through pain.

He has to prove that he can be available week-in and week-out,'' Williams said.It doesn't make a difference if somebody has talent. We've cut a lot of players that have had a lot of talent throughout my coaching years, but if you're not available you become a reporter, a coach, or an insurance salesman, but you're not a professional athlete. ... This is a brutal and tough position. This is a production business. I love seeing Jonathan Casillas practice, but I would like to see him play more.''

NOTES: After releasing Clark, the Saints added OT Jordan Black. ... CB Tracy Porter (left knee), RB Chris Ivory (left foot, groin) and DE Greg Romeus (right knee) still have yet to practice in training camp ... Those who sat out on Wednesday included RT Jon Stinchcomb (left quad), WR Marques Colston (right knee), and Adrian Arrington (left ankle). Payton says he wants to periodically rest players such as Colston and Stinchcomb, who had offseason surgeries. Colston has missed five straight practices, but says he feels well enough to practice and is ``just trying to be smart.''