By Dan Durkin-

(CBS) Once the Bears decided on hiring Vic Fangio as their new defensive coordinator, the signs pointed to the team transitioning from a 4-3 to a 3-4 defense. That was confirmed Wednesday by coach John Fox in his press conference at the NFL Combine in Indianapolis.

“We’re going to be out of a 3-4, terminology wise,” Fox said.

Fox went on to re-emphasize a point he made during his introductory press conference about designation of one scheme being more of a focus on the outside — media and fans — than it is inside the building.

“Sometimes a lot is made – particularly on the outside – about the 3-4 and a 4-3,” Fox said. “Generally, the spacings are very similar. Like all coaching of any defense, it’s really putting your players in the best position to have success. Again, without being on the grass, it’s really hard for me to stand up here and say much more than that.”

The challenge for Fox, Fangio and general manager Ryan Pace now becomes evaluating the existing talent on the roster and determining who fits the athletic profile the team is seeking along the defensive front. Gaps will need to be filled, ideally via the draft but also in the upcoming free agent period.

Just a season ago, the Bears brought in three new defensive ends — Lamarr Houston, Willie Young and Jared Allen — with only Houston having previous NFL experience in a 3-4 front. So there are some potential misfit pieces, but final determinations can’t be made until the team hits the practice field this spring.

Both Houston and Young will be used as outside linebackers in the new scheme, Fox said, but both are working their way back from serious in-season leg injuries.

“We’ll line them (Houston and Young) both up there,” Fox said. “What they become will be up to them. In Willie’s case he’s coming off an Achilles surgery. You know, same thing with Lamarr Houston, coming off an ACL. I had two guys a year ago, Chris Harris and Von Miller, they were coming off ACLs, and they had Pro Bowl seasons. So again that’s all part of the process — getting guys healthy, their rehab, medically getting them ready to play. We’re working on that as we speak daily.”

As for Allen, who has made his career as a hand-on-the-ground right defensive end, Fox is unsure if he’s able to play from a two-point stance.

“I haven’t seen that, so it’d be hard for me to evaluate it until we get him out there, but he’s a good football player,” Fox said. “He’s got good football instincts. And my experience has been that works in a two-point or a three-point.”

Fox pointed out the similarities but also noted the element of surprise the 3-4 presents with which rushers will be sent as an advantage against today’s spread offenses.

“They’re both so similar,” Fox said. “Most people that even call themselves a 4-3 — we were one in Denver – they’re a hybrid of the 3-4. When I started in this league in Pittsburgh, we were a 3-4 defense. The primary advantage of the 3-4 is you’re not locked in to which outside guy is rushing. I think that’s a tremendous advantage in today’s game. Even to the point where you’ve got guys that are a little bit comfortable in dropping and you can drop eight. With today’s spread offenses and some of the things that people are doing with empty sets, that’s an advantage.”

Shea McClellin, the team’s first-round selection in 2012, played a variety of roles in a 3-4 at Boise State. Fox said the coaching staff will evaluate McClellin as both an inside and outside linebacker.

Defensive lineman Jeremiah Ratliff, who when healthy was the Bears’ best defensive player in 2014, was an All-Pro 3-4 nose tackle in Dallas. Ratliff and cornerback Kyle Fuller were singled out by Fox as players the Bears could build a scheme around.

The benefit to the Bears’ scouting department is they now know which types of athletes along the defenisve front the coaching staff is seeking, which allows them to narrow their focus this week in Indianapolis. This upcoming draft class has a talented crop of edge rushers, which could be the position the Bears focus on early in the draft to kick-start the transition to their new look on defense.

Dan Durkin covers the Bears for CBSChicago.com and is a frequent contributor to 670 The Score. Follow him on Twitter at @djdurkin.