1. RB Craig Reynolds
The Lions have three running backs who are locks to make the roster: Jahmyr Gibbs, David Montgomery and rookie Sione Vaki. That leaves Reynolds and a now healthy Zonovan Knight to compete for what looks likely be one roster spot during training camp and the preseason. The Lions are not likely to retain five running backs.
A case can be made for Knight as the runner with more upside. He is certainly younger (23, to 28 for Reynolds). If not for a shoulder injury that sidelined him early last season after the Lions brought him aboard late last preseason, he may have eventually overtaken Reynolds as the No. 3 running back and a top kick returner option.
Reynolds is clearly well-liked by the Lions' coaching staff and his teammates, as a "do whatever is needed" team guy. That stands to give him some level of intangible edge in any battle with Knight, and make him a bit more difficult to overtake.
But if Knight is healthy and stands out during camp, and also shows out in preseason games with plenty of work sure to come his way, he will make it hard for the Lions to choose Reynolds over him on merit.
Reynolds has done well when he's gotten a bigger offensive role for the Lions (see Week 14 and 15 of the 2021 season). In a broad sense other teams surely notice how he's managed to stick around through the team's rise to prominence. If there's no room for him on the depth chart in Detroit, a team looking to add a solid depth running back could easily offer a late draft pick.