BOURBONNAIS, Ill. (AP) Chicago Bears defensive coordinator Vic Fangio might look more appropriately dressed in a lab coat.

Fangio has been mixing and matching with experiments throughout training camp in an attempt to find the right fits for his 3-4 defensive scheme.

''We need to find our D-line,'' Fangio said Friday.

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The new defensive boss, who brought in his 3-4 alignment from San Francisco, not only is attempting to find new linemen but the right fit at inside and outside linebacker.

The line, though, could be his toughest task considering how poorly the Bears defensive line played the past two seasons.

''Somebody's got to step out and be an obvious pick as to who's the starters, who makes the team,'' Fangio said. ''Right now we have one really good player in Jay Ratliff.

''The other guys are fighting for that second, third, fourth, fifth and potentially sixth spot. There's a good fight going on right now.''

The 34-year-old Ratliff has been at nose tackle, and is backed by rookie Eddie Goldman. However, the end spots have been shuffled between Jarvis Jenkins, Ego Ferguson, Will Sutton and Cornelius Washington.

It might all have been easier if Ray McDonald worked out at end after signing a one-year deal with the Bears after a history of domestic violence in San Francisco, but the last accusation against him caused the team to cut him and left Fangio feeling disappointed.

Fangio had recommended McDonald to coach John Fox, general manager Ryan Pace and chairman of the board George McCaskey.

''I don't regret trying to vouch for him,'' Fangio said. ''At the time I believed it was the right thing to do.

''The only thing that I regret is that because it didn't work out, and the club put their faith in my recommendation, and George and Ryan and John took some hits from (media) and (media) really should've been hitting me and not them.''

The early mistake did nothing to diminish Fangio in his new bosses' eyes.

''He may be the most experienced coordinator I've had, as far as number of years in the league with that title,'' Fox said about Fangio, who was a coordinator for Carolina from 1995-98, Indianapolis from 1999-2001 and Houston from 2002-05 before going to San Francisco. ''He's an outstanding teacher.

''Any good coach that's accomplished a lot has to be a good teacher. Vic's no different. He's very good and we're fortunate to have him.''

The hiring of Fangio raised questions early because he teaches the 3-4 and Fox has always used a 4-3. ''I didn't think I was going to hire Vic and say `OK, we're running the 4-3,''' Fox said. ''You've got to let a guy do what he's accustomed to doing and in many of cases how.

''There will be some situational stuff that we may disagree on, and Vic has worked for head coaches before, too. It's standard operating procedure.'' Fitting the pieces from a long-time 4-3 into a 3-4 seems more of the problem with this Bears team than any potential coaching conflict. Fangio has two outside rush linebackers in Pernell McPhee and Sam Acho, but finding their backups from among LaMarr Houston, Jared Allen, David Bass and Willie Young has been one of his bigger challenges. ''I believe I'm solid at linebacker,'' said Houston, a former Raider, who is coming off a torn ACL. ''With the Raiders we were more of a hybrid 3-4.''

It's a drastic departure for Allen after 12 years at 4-3 end, but Young, coming off a torn Achilles, has to make the greatest transition.

''I don't know anything about playing linebacker, so obviously I study day-in and day-out now,'' Young said. ''It's never a day off.''

Young played end in Detroit in a ''wide-9'' formation before coming to the Bears and making 10 1/2 sacks at end. He called the new position unlike any spot he ever played.

''Heck no! No! Not even close,'' Young said. ''I might've had two things to worry about at defensive end regardless of how far out I was, keying the ball and getting the strength call from a linebacker.''