4. LT Taylor Decker
The longest-tenured Lions' player, Decker is the ideal bookend for the Lions at left tackle and a veteran leader who has been through plenty of losing and at times dysfunction. He's steady, reliable and one of the most underrapreciated players at his position in the entire league (no career Pro Bowl selections). He's also no wallflower, off the field or on it.
By all accounts Decker has had an excellent start to training camp. Maybe that Pro Bowl drought ends this year. In any case, at one of the most important positions in the NFL, Decker has things locked down for Campbell and the Lions.
3. Aidan Hutchinson
Hutchinson was everything the Lions could have hoped he be last year as a rookie, coming as the No. 2 overall pick. There were a few early kinks, as expected, but he led all NFL rookies in sacks and quarterback pressures. In the latter weeks of the season, he was graded as one of the best overall edge defenders in the league by Pro Football Focus.
Hutchinson has spoken about how the game is slowing down for him going into his second season. That's a scary thought for opposing offensive lines and quarterbacks. It's also obviously a good things for the Lions, and Campbell's sleep schedule as he may be concerned with the performance of the defense.