CHARLOTTE — The Panthers placed defensive tackle Derrick Brown on injured reserve Tuesday after he suffered a knee injury in Sunday's opener in New Orleans.

Brown, who made his first Pro Bowl last season, played 60 of the 66 snaps in Sunday's game. He will not return this season. He also leaves a significant hole in the defense, one that one person can't replace according to head coach Dave Canales.

"Definitely a huge loss, right? He's one of our best players. That's big shoes to fill," Canales said. "But at the same time, we've got players in there, I want them to know and be encouraged. If you go in, you play with great technique, and you just do your job, we don't need you to make the special plays that Derrick makes.

"Just do your job, help the guys on either side of you and that's the truth of it. If you can play team football with a bunch of guys, you can have success."

The team also waived outside linebacker Jamie Sheriff on Tuesday. He was one of the six players claimed from other teams following cuts.

The Panthers also signed two players to the active roster and two to the practice squad Tuesday.

Veteran special teamers Mike Boone and Lonnie Johnson were signed to the 53-man roster. They began the year on the practice squad, and were elevated to play last week.

The Panthers also signed veteran defensive end DeShawn Williams and cornerback Azizi Hearn to the practice squad.

Williams was here last season and started 10 games, playing in 16. He also played in Denver when defensive coordinator Ejiro Evero was there. He was in camp with the Bills this summer.

Hearn was in camp with the Raiders last year and spent the season on the Patriots practice squad. He played collegiately at Arizona, Wyoming, and UCLA.