OWINGS MILLS, Md. -- Baltimore Ravens safety Matt Elam nearly ran out of breath trying to come up with words to describe Lions wide receiver Calvin Johnson, who will be the main object of focus for the team's defensive backfield Monday night in Detroit.

"Big, fast, athletic, unstoppable, freak,'' Elam said.

Curiously, Elam went in another direction when asked how best to cover the 28-year-old Johnson, who's amassed a club-record 9,184 yards receiving and 67 touchdowns in less than seven years.

"He's pretty old, so I don't know how physical he'll be,'' Elam said. "He's a big guy, but he's older. I guess when they get older they're not going to be as physical, you know what I'm saying? We're going to have to be physical, make him uncomfortable.''

Elam is six years younger than Johnson, but he's also seven inches shorter and around 25 pounds lighter. So he might not want to test his theory about Johnson's physicality in a one-on-one situation in the open field.

Elam said on Twitter on Wednesday night he wasn't insulting Johnson.

I will never disrespect greatness... — Matthew Elam (@ElamVsElo) December 12, 2013

The misinformed rookie only can hope the rest of the defensive backfield does its part to prevent that from happening.

"You've got to know when it's time to double him, when it's time to triple-team him,'' Elam said. "You've got to keep your eye on him, because [Matthew] Stafford wants to get the ball to him.''

Ravens backup defensive back Chykie Brown says the Ravens can't afford to let Johnson's reputation get in the way of their effort to keep him from having an impact on the game.

"We're not going to get scared because of the name on the back of his jersey,'' Brown said. "He puts his pants on just like we do. We've got to out there and do us -- get physical on him, play tough on him.''

Johnson is arguably the most dangerous receiver in the NFL, and the Ravens have yielded 18 plays this season of at least 40 yards -- including a 79-yard touchdown last Sunday to Minnesota's Cordarrelle Patterson, who finished with 141 yards in the snow.

Baltimore's pass defense will be severely tested by Johnson, who despite Elam's assessment does not appear to be anywhere close to being over the hill.