Linebacker Jack Campbell spent his first two seasons in the NFL in Kelvin Sheppard's linebacker room in 2023 and 2024.
As the Lions' new defensive coordinator, Sheppard's room has grown significantly larger in size heading into the 2025 season as it now includes Detroit's entire defense.
"Honestly, the only difference is now he has a mic in his hand and he's in your helmet," Campbell joked last week. "That's been good though. I'm happy for him. He deserves it."
Campbell and Sheppard have worked together closely over the last two seasons as Sheppard has helped mentor Detroit's former first-round pick as the starting MIKE linebacker and signal caller on defense. That relationship has been established which should benefit that side of the ball greatly as they continue to install Sheppard's version of this defense.
"It's been good for me coming in and having to work with him so closely to now have him as the coordinator," Campbell said. "I feel like it allows me to know what he's thinking going into a game week. I'm really excited about that."
Campbell was a limited participant in last Friday's open OTA practice as he continues to rehab a minor hip injury he had fixed after the season, but he's taken part in all the walkthrough install periods and has been at the Meijer Performance Center for all of the offseason training program.
That's been important because Sheppard has described his coaching style as a more holistic learning and training approach. How much better can this player be in his system? Developing and bringing players along and getting them up to the speed is the biggest key this time of year, and Sheppard has already applauded veterans like Aidan Hutchinson and Campbell for how quickly they've picked up the nuances of his defense.
Sheppard has four main principles on defense — assignment, alignment, attention to detail and execution. Having a middle linebacker and play caller like Campbell who embodies those traits is so critical.
Campbell was one of just four linebackers to log at least 125 tackles, five tackles for loss, five passes defended and one forced fumble last season.
View photos from Day 3 of Detroit Lions OTA practice on Friday, May 30, 2025 in Allen Park, Mich.

Detroit Lions tight end Sam LaPorta (87) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions edge rusher Aidan Hutchinson (97) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions safety Kerby Joseph (31) and Detroit Lions wide receiver Tim Patrick (12) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions safety Kerby Joseph (31) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions quarterback Jared Goff (16) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions running back Jahmyr Gibbs (0) and Detroit Lions quarterback Jared Goff (16) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions tight end Sam LaPorta (87) and Detroit Lions safety Dan Jackson (28) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions head coach Dan Campbell during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions wide receiver Kalif Raymond (11) and Detroit Lions safety Kerby Joseph (31) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions wide receiver Dominic Lovett (19) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions wide receiver Tim Patrick (12) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions quarterback Jared Goff (16) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions wide receiver Ronnie Bell (10) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions tight end Sam LaPorta (87) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions tight end Brock Wright (89) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions wide receiver Kalif Raymond (11) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions defensive lineman Myles Adams (66) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions wide receiver Tim Patrick (12) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions edge rusher Al-Quadin Muhammad (96) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions offensive coordinator John Morton during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions tackle Penei Sewell (58) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions tackle Taylor Decker (68) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions defensive coordinator Kelvin Sheppard and Detroit Lions offensive coordinator John Morton during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions offensive lineman Giovanni Manu (59) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions wide receiver Dominic Lovett (19) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions quarterback Hendon Hooker (2) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions edge rusher Ahmed Hassanein (61) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)

Detroit Lions edge rusher Ahmed Hassanein (61) during OTAs at the Meijer Performance Center on May 30, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
"There's a few changes," Campbell said of the defense under Sheppard. "There's some things I'm excited about that the back end is excited about and the guys upfront are excited about. It's going to be good, I think, but you have to learn with it.
"Little nuances within the call that's a little bit different than what coach (Aaron) Glenn did. I'm just excited to see what happens. We have the right guys in the room ... so I'm excited."
It's certainly a lot healthier of a defensive room for the Lions right now than how they finished 2024 with 18 defenders on injured reserve, including key players like Hutchinson, Alim McNeill, Derrick Barnes, Marcus Davenport and many others. Campbell likes the pieces in place and once Sheppard's scheme is fully implemented, he thinks there's no reason Detroit can't have one of the more productive defenses in the NFL in 2025.