Cornerback Terrion Arnold left Detroit Lions practice on Thursday with a leg problem. But on Friday, the former Alabama defensive back returned to the field for the Lions’ first day in pads at training camp as he prepares for his second NFL season.

“Terrion Arnold took a huge leap, in my opinion, this offseason,” Detroit defensive coordinator Kelvin Sheppard said. “He progressed during his rookie year, but he’s come in not only this offseason but this training camp looking like a different guy. His body’s more developed. But also from the neck up, the mental aspect of the game, he’s seeing it faster, he’s feeling the routes faster, so that’s a guy I’ve already seen a leap in.”

After joining the Lions in the first round of the 2024 NFL Draft, Arnold started 15 regular season and one playoff contest and logged 1,023 snaps in the Detroit secondary as a rookie.

“He’s where I would expect him to be going into Year 2 after four days,” Lions coach Dan Campbell said on Friday. “You expected another level of confidence, of maturity and ownership really, accountability, and that’s what you feel right now at this point, which is exactly what we wanted to feel. So like where he’s at going into pads.”

Arnold said he should be a better player after a season of starting experience with a team that posted the best regular-season record in the NFL in 2024.

“I got experience now,” Arnold said on Monday. “Just pride myself on trying to go out there and get the ball. And then just taking it one day at a time. I mean, you know, it just don’t happen overnight. You got to trust the process, and I’m staying down for it. …

“I just feel like that, No. 1, because just coming into a system and then having to play Super Bowl-caliber football night in, night out, Sunday night, Monday night, Thursday night. And then when you have a coach and when you have a team like us, you know that you’re going to get everyone’s best. So just being put in that role and then knowing teams know you’re going to play man and then coming out of college and transitioning into that, into the NFL, you can’t help but get better.”

Arnold said his offseason preparations had focused on “just working on being more of a leader and then working on getting the ball and then just working on the little details. And then just as far as having that one year of experience under your belt, you just can’t get bored doing the little things. So I just pride myself on trying to get here early, focusing on recovery for my body, and then really, really watching film. And then my coaches, (Deshea Townsend and Jim O’Neil), they do a really, really good job of just allowing us to meet with them over time. Like, y’all kind of holding me up right now because I’m fixing to go meet with them.”

Despite injuries to some of its top players, the Detroit defense finished seventh in points allowed among the NFL 32 teams in 2024.

“The standard for us is getting the ball back to the offense,” Arnold said. “I mean, when you can go out there and force turnovers, force takeaways, it’s game-changing plays.

“And then on top of that, we all young and we’ve had a chance to have a year of camaraderie under our belt. Like, that’s very, very rare in the NFL. So, I mean, just seeing the same guys you were lined up with, aside from we replaced Carlton (Davis) with D.J. (Reed), but he’s came in and fell right into place. So when you have a group of guys that could jell together and we hang out together and we do extracurricular activities together. I mean, just the brotherhood is stronger than ever. And when you are able to go out there and have trust that your guy is going to be in the right spot or he could trust me to make this play, it just makes football a lot easier.”

Arnold had one takeaway for Detroit as a rookie with a fumble recovery, but he did not intercept a pass.

“It’s coming, though,” Arnold said. “I mean, once you get one, you know, they just start. They just start coming.”

The Lions will open the NFL’s preseason schedule when they play the Los Angeles Chargers on Thursday night in Canton, Ohio, in the annual Hall of Fame Game.

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Mark Inabinett is a sports reporter for Alabama Media Group. Follow him on X at @AMarkG1.