A knee injury that suddenly has gone from discomforting to debilitating, and is perhaps worse than New Orleans Saints officials originally believed, will keep star offensive left tackle William Roaf out of Sunday's game against the New England Patriots.

And if the suspicions of some team officials are unfortunately confirmed, and Roaf has a tear in the anterior cruciate ligament of his right knee, the seven-time Pro Bowl performer could miss the remainder of the season.

"Right now, I can play with it like it is," Roaf said. "We'll just have to see what they say when they get a better look at it."

Roaf, 31, will visit Dr. James Andrews, the noted orthopedic specialist, in Birmingham, Ala., on Monday for a second opinion on the damaged knee. Saints doctors confirmed he has a tear in the medial meniscus cartilage but now suspect there might be a problem with the ACL as well.

If the ACL is simply stretched, there is no need to repair it surgically, but Roaf probably will have the cartilage fixed with a Tuesday arthroscopic procedure. If the ACL is torn, the severity of the damage will determine his status for the rest of this season. A severe tear would likely mean reconstructive surgery and 6-8 months of rehabilitation.

Even if Andrews finds just cartilage damage, Roaf could miss 2-3 more weeks, and the New Orleans blocking unit would be significantly weakened.

Coach Jim Haslett acknowledged the team is "concerned" about the injury.

A nine-year veteran, and one of the most celebrated left tackles of the past decade, Roaf missed two games earlier this season with a different knee injury. In an Oct. 11 game against Atlanta, he bruised the meniscus and also a bone in the right knee. He recovered through non-surgical rehabilitation and returned to the lineup on Nov. 11.

In his first eight seasons, Roaf missed just four of 128 games. In his place, third-year veteran Daryl Terrell will move into the lineup at left tackle, having started the two games Roaf missed earlier this season.

Len Pasquarelli is a senior writer for ESPN.com.