Since January, the Browns' scouting department has been on a mission to find the next Adalius Thomas or Shaun Phillips.

Or, if the Browns wanted to dream about getting back into the third round of the draft, the next Mike Vrabel or Joey Porter.

Among the NFL's top pass rushers, all four were college defensive linemen who made the transition to linebacker in the pros. All came into the league in the third round or later.

Thomas of the Baltimore Ravens (a Southern Mississippi product) was a sixth-round pick of the Ravens in 2000. Phillips (out of Purdue) was a fourth-round choice in 2004 of the San Diego Chargers. Vrabel (from Ohio State and Walsh Jesuit) of the New England Patriots was a third-round choice of the Pittsburgh Steelers in 1997. Porter of the Miami Dolphins (out of Colorado State) went to the Steelers in the same round in 1999.

Going into the NFL Draft this
weekend, the Browns don't have a pick until the 23rd choice in the fourth round, 122nd overall. But they'll still search for an outside linebacker to pair opposite Kamerion Wimbley, the 13th overall pick in 2006 who played defensive end at Florida State.

''There are a cluster of guys who project to outside 'backer and we're studying them pretty hard,'' Browns General Manager Phil Savage said Feb 28. ''We've been working on that project since the season ended and not necessarily at the highest level of the draft, but more mid-round-type guys we think could develop into outside 'backers.

''That's one of our spring projects — to sort out the half a dozen players we think can make the conversion and put them in an order and see if we can maybe get one.''

There are more fitting role models for players who made the transition. Of the 53 who ranked among the league's top 50 sack leaders in 2007, 13 were linebackers and nine of them played defensive line in college. But five — Shawne Merriman of the Chargers, DeMarcus Ware and Greg Ellis of the Dallas Cowboys, Julian Peterson of the Seattle Seahawks and Calvin Pace of the Arizona Cardinals — were first-round picks.

Because he was director of college scouting in Baltimore in 2000 when the Ravens took Thomas 186th overall, Savage could make Thomas the poster child for the Browns' search.

Thomas had 341/2 sacks in four years at Southern Miss. At 6-foot-2 and 270 pounds, he was a workout phenom, running the 40 in 4.52 seconds, bench-pressing more than 400 pounds and hitting 40 inches in the vertical jump. But as the late Joel Buschbaum of Pro Football Weekly said in its 2000 Draft Preview, Thomas was ''an underachiever who teases with flashes of ability, but lets you down by not seeming to play hard much of the time.''

Mike Mayock of the NFL Network said when searching for what he calls ''conversion guys,'' the typical skill set is ''an undersized athletic defensive end who has some sack production.'' He didn't mention underachieving — another trait the Browns might have to ponder.

''You ask yourself, 'Is he athletic enough to stand up and occasionally drop back into coverage?' '' Mayock said. ''That's where the different drills at the combine and pro day come into play. You're testing their hips, their ability to change direction and movement skills. The reality is it does take kids a period of time to handle the conversion to what the 3-4 is.''

That might be an issue even for a first-rounder. Mayock said he watches only tapes of college players, but understands what happened to Wimbley, who set a Browns rookie record with 11 sacks, then had only five in 2007.

''He's a very talented kid,'' Mayock said. ''In general terms, when you had a rookie year like he had, teams are going to pay a lot more attention in Year 2. They're going to chip you with a running back, put a tight end over you, chip you with a tight end or tackle. You're always dealing with that and you've got to get used to it.''

ESPN analyst Mel Kiper Jr. sees a number of players in this draft who will be asked to make that switch.

''Because of athletic ability and physically because of the way the league is now, those hybrids do go high and are valued,'' Kiper said. ''I've said for seven or eight years that attacking outside linebackers and running backs are going to help you right away.''

Chris Long of Virginia and Vernon Gholston of Ohio State, two who fit the mold, will probably go in the top seven Saturday. Kiper considers Gholston ''the Merriman, the DeMarcus Ware in this draft.''

But Kiper said there are other players of value who could be available from the second round on. One of them is Quentin Groves, a player with the inconsistent label who made a pre-draft visit to the Browns.

Groves doesn't mind the position switch he'll soon be asked to make. In fact, he's embraced it.

''I want to be the first quote-unquote 'tweener taken.'' Groves said at the combine. ''It's going to be hard, because you've got Vernon up there.''

He thinks that players like him will continue to make an impact.

''The game is changing. The game is going more to speed,'' Groves said. ''It was rare back in the day that you found a guy 260 pounds who could run a 4.4 40 or who could bench-press just as strong as a 3-technique. Now you can find those guys. They're coming up slowly but surely.''