The Detroit Lions have a number of established and rising stars on defense with players like Aidan Hutchinson, Kerby Joseph, Brian Branch and others.
But maybe one of the most important defenders for the Lions in 2025 will be MIKE linebacker Jack Campbell. The third-year linebacker out of Iowa has really taken ownership of Kelvin Sheppard's defense, and he and Alex Anzalone are kind of the glue in the middle that connects the front four to the back end and makes it work seamlessly.
"I've had the honor of coaching Jack since he was drafted," said Sheppard, who was Campbell's position coach his first two seasons before taking over as DC this season. "Jack's a player, out of everybody, he's never had any other voice in his head. He knows what I'm thinking, we're in lockstep with one another, and we spend a lot of time together, quite frankly."
Campbell has the green dot and makes the defensive calls. Sheppard will be in his ear all season as they try to come up with the right answers to what they're seeing on the other side of the line of scrimmage.
When Campbell came back for the offseason training program, he and head coach Dan Campbell sat down and had a conversation about him stepping up and making the defense his. He's the MIKE, he's in the middle, and the Lions have the trust in him to get them in the right plays and be their leader because of the way he studies and prepares.
"Look he was, when he came in (as a rookie), he was pretty good," Dan Campbell said. "He was one of these guys that was a little bit ahead of everything mentally and now to see where his growth is, it's impressive.
"He's done an outstanding job. He's got a good feel of the game, he understands the game, he knows what we're trying to do defensively, he did with AG (Aaron Glenn) and even more so now with Shep. And so with that, we're going to give him a lot more, he and Alex (Anzalone) both."
Campbell was one of only four linebackers in the NFL last season to record at least 125 tackles (131), five tackles for loss (5), five passes defended (5) and one forced fumble (1). It's not out of the realm of possibility that he could become a 150-tackle player in his third season.
View photos from Day 5 of Detroit Lions training camp on Friday July 25, 2025.
Detroit Lions wide receiver Jameson Williams (1) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions running back David Montgomery (5) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions wide receiver Jameson Williams (1) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions running back Jahmyr Gibbs (0) and Detroit Lions safety Kerby Joseph (31) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions quarterback Jared Goff (16) and Detroit Lions running back Jahmyr Gibbs (0) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions offensive lineman Christian Mahogany (73), Detroit Lions tackle Dan Skipper (70), Detroit Lions quarterback Jared Goff (16), Detroit Lions tight end Sam LaPorta (87), Detroit Lions running back Craig Reynolds (13) and Detroit Lions wide receiver Amon-Ra St. Brown (14) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions safety Kerby Joseph (31) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions quarterback Hendon Hooker (2) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions cornerback Terrion Arnold (6) and Detroit Lions wide receiver Jameson Williams (1) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions defensive back Brian Branch (32) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions cornerback Dicaprio Bootle (17) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions wide receiver Amon-Ra St. Brown (14) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions assistant head coach/wide receivers coach Scottie Montgomery during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions guard Netane Muti (52) and Detroit Lions center Kingsley Eguakun (65) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions offensive lineman Giovanni Manu (59) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions cornerback D.J. Reed (4) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions tight end Kenny Yeboah (88) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions wide receiver Amon-Ra St. Brown (14) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions wide receiver Amon-Ra St. Brown (14) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions cornerback Amik Robertson (21) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions head coach Dan Campbell during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions guard Kayode Awosika (74) and Detroit Lions offensive lineman Tate Ratledge (69) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions punter Jack Fox (3) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions cornerback Morice Norris (26) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions linebacker Derrick Barnes (55) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions linebacker Jack Campbell (46) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions offensive coordinator John Morton during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions wide receiver Jackson Meeks (83) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions defensive lineman Keith Cooper Jr. (64) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions cornerback Stantley Thomas-Oliver III (38) and Detroit Lions wide receiver Jackson Meeks (83) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions wide receiver Isaac TeSlaa (18) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions wide receiver Dominic Lovett (19) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions tackle Penei Sewell (58) and Detroit Lions edge rusher Aidan Hutchinson (97) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions linebacker Jack Campbell (46) and Detroit Lions tight end Sam LaPorta (87) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions edge rusher Aidan Hutchinson (97) and Detroit Lions tackle Dan Skipper (70) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions running back Craig Reynolds (13) and Detroit Lions linebacker Trevor Nowaske (53) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions wide receiver Isaac TeSlaa (18) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions wide receiver Ronnie Bell (10) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions tight end Sam LaPorta (87) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions wide receiver Ronnie Bell (10) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions edge rusher Aidan Hutchinson (97) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions linebacker Jack Campbell (46) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions defensive coordinator Kelvin Sheppard during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions edge rusher Marcus Davenport (92) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions edge rusher Ahmed Hassanein (61) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions General Manager and Executive Vice President Brad Holmes during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
Detroit Lions wide receiver Malik Taylor (86) during training camp at the Meijer Performance Center on July 25, 2025 in Allen Park, Mich. (Jeff Nguyen/Detroit Lions)
The mental aspect of the game was where Campbell said he took his biggest leaps last season and his goal for this season is to eliminate any and all mental errors. That comes with serious preparation.
"I'm just out there playing football and trying to be the best Jack Campbell I can be every single day. Nobody else," Campbell said Friday. "Whatever I have to do to make this defense the best defense it can be, I'm going to do it."
