STARKVILLE, Miss. -- Dan Mullen is meticulously studying defensive game film of three teams he isn't facing anytime soon. His laser pointer highlights some players he'll never see and formations that probably won't quite look the same in the coming weeks.

Instead of watching South Alabama, South Carolina and LSU -- Mississippi State's first three opponents this season -- a frustrated Mullen sees Eastern Illinois, Auburn and Wisconsin. The connection? All the defensive coordinators from the latter schools are now at the former.

Then, Mullen underscores his coaching challenge this season by highlighting his team's personnel losses on offense. Instead of having three veteran receivers with at least 400 yards each, as he had last season, Mullen is left with one, senior Fred Ross. He isn't a slouch, but he can't make up for the loss of De'Runnya Wilson and Fred Brown.

Instead of having a solid, experienced body next to Richie Brown at linebacker, Beniquez Brown (last year's No. 2 tackler with 99 stops, 11 for loss) opted for the NFL after last season.

Mullen has zero healthy cornerbacks with any career interceptions, and he'll have a starting quarterback not named Dak Prescott for the first time since the 2012 season. Only four offensive players return double-digit starts, while five hit that number on defense.

The Bulldogs' two-deep depth chart is comprised of 14 underclassmen on offense and 12 on defense. So when it comes to figuring out the identity of his 2016 football team, Mullen is still searching.

"I don't know. We have to see," he said. "There are so many new faces to me. ... There are a lot of guys who are going to play significant roles that have either never played or have played very minimally.

"It's not like we have the guy who's won Best Supporting Actor for three years going into his first lead role. We have a bunch of extras now that are going into lead roles."

Yes, but even Leonardo DiCaprio started out as an extra.

"But he didn't go from extra right into the lead," Mullen said with a laugh.

True. Before DiCaprio stole our hearts as Arnie Grape in "What's Eating Gilbert Grape," he was simply an uncredited classmate of Darlene's on the hit show "Roseanne."

It took DiCaprio a few years to garner Oscar-worthy acclaim, but Mullen doesn't have a few years. He has a few days before his season opener against South Alabama. He'll then have a few more days to prepare for SEC opponent South Carolina.

Mullen, who hates the term "gamers," hopes guys who are struggling in practice shine under the bright lights. While he's become more impressed with his team as a whole as the weeks have gone by, he's still unsure how this team will react when players in other uniforms line up.

It's kind of like how he's playing his quarterback situation. He's waiting on a leader. Nick Fitzgerald, Damian Williams and Nick Tiano are all listed on the opening depth chart, but to this point, no one has grabbed the position.

A starter for South Alabama could come as soon as today, but Mullen isn't calling Saturday's starter the South Carolina starter.

"It's sorting itself out," Mullen said. "To this day, no one has jumped up and separated himself to be the guy. It's not done this [steadily moves his right hand about a foot above his left hand]. It's kind of done this [leaves right hand level with the left]. I have a good idea where I'm at and who's going to be the starter ... but I'm going to play more than one in the first game. I can guarantee you that."

When you're a program like Mississippi State, you're methodically building a winner. There's no quick-fix approach, which is why the numerous early defections and medical redshirts, plus regular attrition, have helped create a negative trickle-down effect of inexperience at multiple positions.

"There are a bunch of guys that are supposed to be on the roster right now that aren't on the roster," Mullen said.

Because the coach has fewer experienced players, he'll have to play the better of the two at each position longer in games. If there are 80 offensive plays in a game, they'll get split this season close to 60/20 because of inexperience, Mullen said. For instance, if he still had Wilson and Brown at receiver, those numbers would be closer to a 40/40 split at each spot. That means tired, less fresh legs just in time for the heart of SEC play.

Defensive coordinator Peter Sirmon sees that the inexperience, coupled with a brand-new scheme, is taking a toll on his defense at times. It isn't the youth he's concerned about, it's the four returning starters listed on the depth chart. A.J. Jefferson, Johnathan Calvin and Nelson Adams have the only career starts on the defensive line. (Nick James, who has 10 starts, isn't listed after his recent arrest.) Of the 14 career starts among linebackers on the roster, Brown owns 13 of them. And the secondary has lost cornerbacks Tolando Cleveland (10 starts) for the season to an ACL injury and Cedric Jiles until mid-October because of a broken arm.

"How are we going to become consistent performers? That's going to be the challenge," Sirmon said.

Mullen isn't necessarily painting 2016 as doom and gloom in Starkville. He has proved his ability to develop quarterbacks, and Sirmon thinks there's some sneaky-good talent inside a mentally tough defensive unit. But it will take time for this team to mature on the field.

"I want to see how they are going to handle it when the lights come on," Mullen said.