The first individual is linebacker Jarrad Davis, the team's first-round pick (No. 21 overall) in the 2017 NFL Draft.
The last regime in Detroit was so disappointed with Davis' production through his first three seasons in the league that it decided to decline the fifth-year option on his rookie deal before the start of the 2020 campaign.
It led to the Florida product, now a free agent, suiting up for less than 30 percent of the Lions' defensive snaps in the 14 games that he played in -- his lowest amount of playing time since entering the league.
Yet, he still impressed Campbell during the new Detroit head man's film study sessions with new Lions general manager Brad Holmes.
"Look, I can't tell you what we're going to do in free agency. But, when you state it like that, Jarrad Davis, there's something about that guy, man," Campbell told The Detroit News. "Things I hear about the way he was coached, and just knowing the ability and aggressiveness, he intrigues me. He pops off the tape, and you feel like, man, can we help this guy? Can we make this guy a better player?"
Davis logged just 46 total tackles, including a lone tackle for loss, in a career-low four starts a season ago.
So, if Campbell & Co. truly want to bring the 26-year-old back to the Motor City this offseason, it doesn't appear there will be an overwhelming amount of competition from other organizations.
Halapoulivaati Vaitai "intrigues" Campbell
The other player that caught Campbell's eye during his film watching sessions was offensive lineman Halapoulivaati Vaitai.
The 27-year-old was largely a disappointment in his first season in Detroit.
He managed to play in only 10 games, after battling the injury bug all year long.
And, when he did play, he wasn't very good. He permitted six sacks on the season -- the most of any Lions lineman in 2020.
Yet, Campbell saw enough on tape out of "Big V" to be "intrigued" by the big man.
"Shoot, man. I'll be honest, Big V intrigues me," Campbell expressed to The Detroit News. "I'm watching this guy, and I'm like, 'All right.' The more tape I've watched on Big V, he's growing on me. That's a good thing. I think he's kind of versatile, and I think there's some things he can do."
Vaitai will be a major reclamation project for Campbell and his staff in 2021. However, he remains hopeful that the Texas native can turn things around.
"I'm encouraged, I really am," Campbell said. "There's some stuff here. I can't guarantee you what's going to happen next year. But, I know we're going to do everything we can to create an attitude and a confidence. Whatever is in this building, we must develop and make better. Whatever they were last year, they have to take one step forward. They have to. That's our job."
More from SI All Lions:
Get the latest Detroit Lions news by joining our community. Click "Follow" at the top right of our SI All Lions page. Mobile users click the notification bell. Be sure to follow us on Twitter @DetroitPodcast.