CHARLOTTE, N.C. -- Carolina Panthers tight end Greg Olsen says strong safety Kam Chancellor is the key to Seattle's top-ranked defense that faces New England on Sunday in Super Bowl XLIX.

Olsen shared his thoughts on Tuesday during an appearance on ESPN's "The Herd with Colin Cowherd” radio show broadcast live in Arizona.

"He's the cog," Olsen said of Chancellor. "He's the main part of them. With the flexibility he gives them to be the eighth linebacker type, the eighth guy in the box, the fourth linebacker in base, but then he also is a D-back ... that's the combination that makes that style of defense work.

"Six-two, 230, 4.4 guys. They're not exactly just popping them out every year. It's rare."

Olsen speaks from first-hand experience. In four games against Seattle since 2012, often covered by Chancellor, the 2014 Pro Bowl selection had a combined 12 catches for 167 yards and no touchdowns.

He had one catch for 16 yards in a 13-9 loss to the Seahawks on Oct. 26 in Charlotte, and four catches for 58 yards in a 31-17 loss at Seattle in the NFC divisional playoff game.

Olsen doesn't envy what New England tight end Rob Gronkowski will face in Chancellor.

"It's a tough matchup," Olsen said. "The team that can just stay with their normal stuff and don't need to reinvent themselves on defense to stop the Gronkowskis of the world, they have an advantage."