EL SEGUNDO, Calif. — The Los Angeles Chargers are reaching the point of training camp when evaluation begins to turn into decision-making.
With another preseason game approaching and roster cuts looming, defensive coordinator Chris O'Leary is looking for more than splash plays from a defense filled with established veterans and young players fighting for roles. He wants a unit that understands exactly how it intends to play.
"Execute fast, violent, and get off the field," O'Leary said Sunday after the Chargers practiced at The Bolt. "To play fast and violent, you got to know what you're doing, you got to be able to anticipate what the offense is doing. You got to be communicating to each other."
It has been a consistent message from O'Leary throughout his first training camp as the Chargers' defensive coordinator. O'Leary returned to Los Angeles this offseason after spending the 2025 season as Western Michigan's defensive coordinator, replacing Jesse Minter after Minter became the Baltimore Ravens ' head coach. O'Leary previously served on Jim Harbaugh's Chargers staff as a safeties coach.
The transition has given O'Leary an opportunity to put his own stamp on a defense that includes stars such as Khalil Mack and Derwin James Jr., while also evaluating a collection of rookies and young players trying to establish themselves before the regular season.
Two of the more intriguing players in that group are rookie safety Genesis Smith and undrafted outside linebacker Nadame Tucker, who arrived in Los Angeles through very different paths but find themselves trying to accomplish the same thing: earn the trust of the coaching staff.
Smith, a fourth-round pick in April's NFL draft, has steadily emerged as one of the Chargers' young defensive players to watch during camp. The Chargers entered the summer with a crowded safety room led by James and veterans Elijah Molden and Tony Jefferson , along with RJ Mickens and Kendall Williamson , making every practice and preseason snap important for Smith.
O'Leary believes Smith has begun moving beyond simply trying to survive his first NFL training camp.
"His ceiling is so high," O'Leary said. "I think he's progressing really well right now. You saw him make some tackles. You know, he had an opportunity at an interception. He kept his feet in the end zone. But you can see the flashes when he's out there."
For O'Leary, one of the most encouraging developments has been seeing Smith become more comfortable within the defense instead of thinking his way through every assignment.
"He's playing football," O'Leary said. "He's not out there thinking, which can get rookies a lot of times. So I think he's in a good spot and he's going to keep getting better."
Smith acknowledged the biggest adjustment has been learning how to combine the instincts that made him successful in college with the discipline required within an NFL defense.
"The speed of the game's a little bit quicker," Smith said. "If you're a football player, I feel like you can ball at any level. Pro ball's still balling to me at the end of the day. Just learning a different playbook, just trying to build trust with the coaches so they would trust me."
That word — trust — repeatedly came up when Smith discussed his first NFL camp. He said he has tried to spend as much time as possible at the Chargers' facility learning the defense while leaning on the veterans around him.
"I'm just trying to soak in everything I can from the vets," Smith said. "I'm in a really good room with all the safeties. Everyone's going to take me and lift me. I've just been trying to spend as much time as I can in this building, trying to get all the plays down so I can build trust as fast as possible."
O'Leary said Smith possesses the natural ability, instincts and ball skills coaches look for at safety. The challenge is teaching him when to trust those instincts and when to remain within the structure of the defense.
"You love coaching guys where you gotta say 'whoa' rather than 'go,'" O'Leary said. "For him, that's kind of been a learning curve — being detailed, being consistent where he's at. So we're growing there."
Tucker's relationship with O'Leary goes back further.
The undrafted rookie played for O'Leary last season at Western Michigan, where he tied for the Division I lead with 14.5 sacks after entering the season without a career sack. O'Leary's Western Michigan defense ranked ninth nationally in scoring defense, and Tucker has credited his former college coach with helping unlock his potential.
Now Tucker is attempting to follow O'Leary from Kalamazoo to Los Angeles and turn an undrafted opportunity into a spot on the Chargers' roster.
"Starting off with believing in me," Tucker said when asked what O'Leary did for him at Western Michigan. "I feel like as a coach, pouring into your players and uplifting them, that means a lot, especially coming from my journey. A lot of coaches, they never believed in me."
Tucker said O'Leary gave him a blueprint for what an NFL player should look like and how one should prepare, something that helped transform his final college season.
The relationship has given Tucker some familiarity during his first NFL camp, but he knows it won't guarantee him anything.
"As an undrafted guy, you could kind of feel like you're out there by yourself," Tucker said. "It's just good to have some familiar guys that know your game and know who you are as a person. But at the end of the day, it's a business and you got to come out here and, whether you know somebody or not, you got to come out here and perform."
Tucker is competing in an outside linebacker room headlined by Mack and Tuli Tuipulotu and featuring first-round pick Akheem Mesidor , Bud Dupree , Kyle Kennard and Garmon Randolph. His connection with O'Leary and his college production make him one of the more compelling players competing for a spot near the back end of that group.
For now, Tucker is taking advantage of the opportunity to learn from Mack and the other veterans around him.
"It's been fun, honestly, just learning from guys like Khalil," Tucker said. "The guys keeping me on my A-game, learning from them, trying to be a Pro Bowler. So it's just stacking good days."
The biggest difference between college and the NFL, Tucker said, has been discovering how much seemingly minor details matter. Hand placement and eye discipline are among the techniques he said he did not emphasize enough during his college career but has quickly learned can determine whether a player succeeds at this level.
Smith is going through a similar education in the secondary. The players are bigger and faster, the playbook is more complex and the margin for error is smaller, but he said his instincts haven't disappeared.
"Football is football," Smith said. "They're doing a bunch of different formations to get to the same thing. … The individual players, like running backs, [are] a little bit bigger, the offensive line a little bit bigger, receivers a little bit faster or twitchier."
That is ultimately what the final weeks of camp will be about for O'Leary and the Chargers: finding out which players can translate talent and flashes into consistent NFL football.
The Chargers have veterans who already know they will play significant roles this season. What remains to be determined is which young players will earn the opportunity to join them.
For Smith and Tucker, every practice is another chance to make that case.
For O'Leary, the standard remains simple.
Play fast. Play violent. Execute. And give the coaches a reason to keep putting you on the field.
