Outside linebacker a year ago featured Julian Peterson and Ernie Sims as the starters. This year, with Sims being traded to the Eagles in the offseason, it will feature Peterson and Zack Follett, who has gone from a practice squad member to a special teams player to a starter in less than a year. While that is a little scary because Follett is still unproven as a linebacker and depth isn't all that great behind him, there's no doubt people are looking forward to seeing the Pain Train making plays this upcoming season.
The backups at outside linebacker right now are a former Panther, a former Bill and a pair of Campbells. The former Panther and Bill, Landon Johnson and Ashlee Palmer, were brought in largely for special teams reasons. With Danny Crossman, Carolina's ex-special teams coach, taking over the position in Detroit, he wanted to bring in guys who excel on special teams and will make the Lions' kick/punt coverage better. Johnson especially fits the bill, although he does have starting experience from his days in Cincinnati.
As for the two Campbells, both are fighting to make the roster. Caleb Campbell, as we all know, is a draft pick from a few years ago who just rejoined the team this year after fulfilling some of his military requirements. Although Campbell has quickly shown improvement, he is definitely on the roster bubble. Lee Campbell is on the bubble even more, as he was already released once by the Lions. He was only brought back after Jordon Dizon's injury, although the Lions have him listed as an outside linebacker rather than a middle linebacker.
Need going forward?
Although there has been talk ever since the Sims trade that a veteran linebacker would be brought in, the Lions have yet to do anything along those lines. I still think it's possible if Follett shows that he may not be ready to be a starter just yet or to simply shore up depth at the position, but so far the Lions have moved forward with what they already have for the most part.