But in the NFL, few teams succeed in finding linebackers like the Ravens. They can take first-round picks, late-round selections or rookie free agents and turn them into Pro Bowl performers.
"First, there are two traits you have to have, and that's to be able to run and be a good tackler," Ravens general manager Ozzie Newsome said. "Secondly, don't underestimate what those linebackers are learning in the room from No. 52 [Lewis]. Nobody understands the game better, the preparation needed, and it has to rub off on them.
"And then third, we utilize players at linebacker that have versatility," Newsome said.
And speed. Ravens linebackers have always been undersized but incredibly fast. The Ravens like the hybrids. For instance, Boulware was a defensive end at Florida State, and Suggs played the same position at Arizona State.
Johnson was a small defensive tackle at Alabama. Thomas was a pure pass rusher at Southern Mississippi. But once they came to Baltimore, they made the transition to outside linebacker.
It wasn't easy, but it wasn't that hard, either.
"Rex Ryan, Mike Nolan and Marvin Lewis have always been able to take those kinds of players and fit them into our scheme," Newsome said. "We look at what a guy can do, not what he can't do, and then we structure things around him to limit his weaknesses."
For Suggs and Boulware, it was a matter of learning to play on two feet instead of coming out of a three-point stance. The Ravens say they saw a lot of toughness in Johnson at Alabama, but there aren't too many 265-pound defensive tackles in the NFL.
Lewis and Scott were considered undersized coming out of college. The Ravens had another barometer, though, for Lewis.
"Ray didn't measure up to the height-and-weight chart," Newsome said, "but he sure did on the football meter. All he did was make every tackle on the field."
There is no debate about Lewis as a mentor. Even though he has had several position coaches himself, Lewis has been the constant in the linebackers' meeting room.
When practice is over and other players and coaches are headed home, Lewis returns to the film room with a trail of young linebackers behind him.
"We have a lot of guys who just love football," Lewis said. "Me, as the leader, I just love tutoring them and trying to make the game slow down for them and try to get them to really understand what the next opponent is all about."
Because of their flexibility and athleticism, many of the Ravens' linebackers are interchangeable. Most of them can bring pressure on the outside or drop into coverage or play weak or strong side.
Barnes, in his second year, is one of the good, young ones. The Ravens have some other good prospects such as second-year players Prescott Burgess and Edgar Jones, who recently moved to provide depth at tight end.
And there are two good-looking rookies in Gooden and McClain. Gooden, out of the University of Miami, was one of the Ravens' top special teams performers until a hip injury forced him to injured reserve.
McClain got his first sack last week. Like Gooden, he is making a name for himself on special teams.
"Ted Marchibroda taught me that if a young player was successful on special teams, there was a good chance he was going to be successful on offense and defense, and the linebackers are the core of our special teams," Newsome said.
They have also been the foundation of the defense for more than a decade. At the end of the season, though, Lewis and Scott will become free agents. The Ravens also have to negotiate with Suggs, the team's designated franchise player.
It's highly unlikely the team can sign all three because that would be a lot of money invested in one position.
But if the Ravens don't, they'll be in good hands because of the younger talent.
"At the end of the season, we'll sit down and talk with all three [Suggs, Lewis, Scott]," Newsome said. "These younger guys are under contract for a few more years, and they've been around Bart and Ray. They have learned from two of the best in the business."
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