New Orleans Saints starting left tackle Terron Armstead is set to undergo surgery on a torn labrum Monday, putting him on the shelf for 4 to 6 months, according to Ian Rapoport of the NFL Network.

The news is concerning for New Orleans, who haven't gotten a healthy season from Armstead since signing him to a 5 year extension last year.

When healthy, Armstead is one of the best left tackles in football.

Last year, Armstead began camp on the PUP (physically unable to perform list). He dealt with knee and quad injuries throughout the season, finally being placed on injured reserve before week 15.

The Saints drafted offensive tackle Ryan Ramczyk at the end of the first round in the NFL Draft two months ago. Ramczyk has yet to sign his contract, and was unable to participate in rookie camp, OTAs or minicamp as he recovers from hip surgery.