1. Eric Reid: There might be teammates who make bigger plays and play with more flash and sizzle, but nobody serves more as a glue guy or is more vital to the Tigers' defensive chemistry than the athletic and versatile Reid. The former Dutchtown standout will be particularly important to LSU with 2-3 new starters in the secondary, depending on which scheme defensive coordinator John Chavis puts the Tigers in. Reid tied for the team lead with 76 tackles last season in 13 games and showed the knack for big plays. A key against the run because of his nose for the ball and ability to ready plays quickly and adjust, Reid is also likely to get more chances in pass defense with offenses geared to avoid Tyrann Mathieu because of his disruptive nature. With some inexperience at corner, look for Reid to be more of a factor coming in over the top or when he sniffs a play out.
2. Tyrann Mathieu: No question who the first name is that rolls out when most people talk about the Tigers' defense, and Mathieu has certainly earned that distinction. Without Morris Claiborne, Mathieu will be huge as a cover corner when LSU is in a base package, but will opposing quarterbacks give him a chance to make game-changing plays or avoid him like the plague. Whether he stays on one side of the field or roams, Mathieu will find a way to hunt down the ball and big plays. Can he be as destructive as last season, though, or was last season lightning in a bottle? That remains to be seen, and if there aren't as many chances to make momentous plays, Mathieu will have to settle in and help in other ways. It's a safe bet Mathieu will find a way to make an impact one way or another.
3. Kevin Minter: For the Tigers to take a step forward defensively, the linebacking corps must play a much bigger role and Minter is the most experienced member of the group back in the fold. Offenses were able to attack the middle of the LSU defense at times last season with big backs and passes underneath to the tight end. It's also important that Minter take on more of a leadership role on defense now that he's a year older, which means being more vocal and doing whatever he needs to do to align his other teammates in the front seven. Minter has a similar challenge to new quarterback Zach Mettenberger – he needs to be good, but not great, and limit his mistakes and missed run fits to make sure the Tigers don't slip at all and become susceptible to the run.
4. Anthony Johnson: Mike Brockers and Bennie Logan made it awfully tough for the younger LSU defensive tackles to get on the field much in 2011, but Johnson saw time in all 14 games and recorded 12 tackles, 3 behind the line of scrimmage. That taste of big-time football needs to fuel Johnson and motivate him to play like the top defensive tackle in his class, which he was pegged as coming out of O.P. Walker in 2011. Logan is back and proved what he can do last season, and he'll need Johnson to blossom quickly to take off double-team pressure and give quarterbacks twice the reason to worry about who's coming at them in passing situations. Johnson may be LSU's best interior lineman against the run, and that could be a huge boost as the ends adjust to what they need to do to make sure the edges aren't exposed against SEC offenses built around the read option. Johnson showed up at LSU with massive expectations and the gut feeling is that he's about to start meeting them this season.
5. Barkevious Mingo: Nobody will ever question Mingo's athleticism and threat to blow up a passing play because of his greasy-fast speed off the edge as a pass rusher. What he must do now in more of a full-time role is show he can play with more discipline and self-control and not run himself out of running plays. There won't be many players on the field able to escape Mingo if he can stay where he needs to be on the field. He is even more of a potential asset in pass coverage because of that athleticism. There isn't as much depth at the ends as there has been in the past, so Mingo will get a legitimate shot to be a full-time option opposite Sam Montgomery. If Mingo can lock down the starting job and render Jermauria Rasco and Lavar Edwards as the more situational ends, that looms as a very good sign for the Tigers.