LSU enters fall camp seeking replacements for Heisman Trophy-winning quarterback Jayden Daniels and a pair of his wide receivers, Malik Nabers and Brian Thomas, who all landed in the NFL as first-round picks in April.But the focus for head coach Brian Kelly isn’t on the skill positions as the Tigers get back on the field after posting a 10-3 record (6-2 SEC) last season.The Tigers were 82nd in total defense and 81st in points allowed at an average of 28 per game. LSU’s defensive staff was entirely replaced in the offseason. Kelly hired former LSU linebacker Blake Baker as defensive coordinator.”It’s about players truly wanting to be part of those 11 guys,” Kelly said of Baker, who was previously Missouri’s defensive coordinator. “Blake’s ability to put that together has been evident.”It won’t take long for the first measurement of the Tigers’ progress. LSU gets a massive test in the opener against Southern California in Las Vegas on Sept. 1.Kelly said redshirt junior quarterback Garrett Nussmeier has to prove in games what he has shown in meetings and walkthroughs — that he has the qualities needed to become a great player. The first sign of his ability to translate traits into performance was in the ReliaQuest Bowl win over Wisconsin, his only career start in 18 games.He threw for a career-high 395 yards with three touchdowns and completed 31 passes. Nussmeier has waited four seasons for the full-time role.”His persistence, his patience, his leadership — we’re excited to watch him lead our team this year,” Kelly said.