MOBILE, Ala. – Much about the schemes depends on players.

That much was clear talking to the Jaguars' new offensive and defensive coordinators at the Senior Bowl Tuesday – that whatever the specific concepts and schemes, they will be designed to enhance the players' strengths.

But there was at least one significant specific learned Tuesday, too:

The Jaguars' defense, long a four-linemen, three-linebackers scheme, will remain that way under new head coach Gus Bradley and coordinator Bob Babich.

"We'll definitely be 4-3," Babich said Tuesday morning during the North practice at Ladd-Peeples Stadium, which will be played Saturday afternoon in Mobile.

"We'll have some basic philosophies that we're going to incorporate scheme-wise. There are going to be a lot of different things we'll look at. We're going to look to play fast, and we want to get better every day. I think the guys will really gravitate to what we're doing."

Babich, who worked with Bradley at North Dakota State, spent the last nine seasons with Chicago and was defensive coordinator three of those seasons.

Offensive coordinator Jedd Fisch - like Babich, hired this past Saturday, three days after Bradley's hiring - has been the offensive coordinator at the University of Miami the past two seasons, and also has worked under respected offensive coaches such as Steve Spurrier and Mike Shanahan.

"We've run different offenses everywhere I've been," Fisch said. "We're going to go through the evaluation process of our players, and see what our players do best. We want to put our players in a position where they can succeed."

Bradley, who worked with Fisch in Seattle in 2010, called Fisch an "innovative" coach.

"It was out there that he wanted to get back in the NFL," Bradley said, adding that Fisch could bring an element of the quarterback-run concepts that have become a trend in the NFL. "He had the interest of many teams. He's going to be very good for us."

Of Babich, Bradley said, "Our philosophies mesh and our terminologies are very similar, so he's a great addition."

Fisch said he wouldn't have a clear idea of the specifics of the scheme until he and the coaches begin to evaluate the roster.

"I can tell you we're going to do everything we can to get the best matchups for our players," Fisch said. "You have to be a balanced team. You have to have a decent amount of ability to get in and out of tempos. I think that's what the league has gone to. You have to be multiple. You have to be hard to defend. We don't want to be a team that's easy to defend.

"We want to be able to give a bunch of different looks, and you have to be explosive."

Also:

• New General Manager David Caldwell said the building process will be based primarily on the draft. "We're going to be a heavily-draft-built team," he said. "We're going to do this from the ground up, and start with the draft. We'll supplement through free agency if we have to." Caldwell also said his draft philosophy is largely "needs-based," adding, "If it's comparable, we'll go with the greater need. You have to go through draft management. You may fill a need in the second or third round versus your primary need in the first round. As long as have a need in the first round you try to get the best available player to fill that need." Caldwell said he is more apt to focus on need early in the draft with a focus best available player later in the draft. "You have to be calculated in your approach," Caldwell said. "If you're a drafter of a team, you can't select the same position over and over and over."

• Caldwell said evaluation of the Jaguars' roster will begin after the Senior Bowl, and said he's not necessarily looking at a complete roster overhaul. "We're looking to build on what we have," Caldwell said. "We're not looking to tear down what we have. To build on the players we have right now is the key for us."

• The hiring of Babich as defensive coordinator meant that Babich will now work for Bradley, whom Babich had on staff when he was the head coach at North Dakota State. Bradley worked for Babick there from 1997-2002. "It's a neat deal," Babich said. "The good thing is we've been friends forever, but he's the head football coach and I understand that. It's a unique dynamic, but it's definitely something we feel good about. It's not going to be a problem."

• Fisch said while he was hired within days after Bradley took the head coaching job last Thursday, the interview was really the year he and Bradley spent working together in Seattle. "You're interviewing for the job while you're in the job," Fisch said. "Every day you go and work as hard as you can work, then your next job comes because of your work ethic. I think that's what Gus knew of me, and how well we worked together. We had a great cooperative relationship. I think the interview really happened when we were in Seattle."

• Caldwell said he has spoken briefly with Jaguars running back Maurice Jones-Drew, and that he has no problem with the three-time Pro Bowl selection rehabilitating in California. Jones-Drew underwent foot surgery shortly before the end of the regular season. "We want what's best for Maurice," Caldwell said. "He has to do what's best for him."

• The decisions to retain wide receivers coach Jerry Sullivan and linebackers coach Mark Duffner were easy ones, Caldwell said Tuesday. The team opted to retain the pair on Monday. "Jerry's done a great job with those young receivers," Caldwell said of Sullivan, adding that the 20-year veteran NFL coach could be valuable as a sounding board for Bradley. "Our players really like him and respect him," Caldwell said. "Every player he's coached has really performed well." Caldwell said the same was true of Duffner, the longest-tenured coach on the Jaguars' staff. "It was a good fit," Caldwell said.

• Former defensive line coach Joe Cullen has taken a similar position with the Cleveland Browns, Bradley confirmed Monday.

• Caldwell said while the team has yet to focus on the specifics of the draft-day approach, he will be open to anything, including possibly trading the No. 2 overall selection. "We'll do what's best for the organization," he said.