Lions beat writer Kyle Meinke:
The most impressive rookie of minicamp, easily, has been tailback Ameer Abdullah. It's hard to say much of anything substantive about a tailback, when there are no pads and no contact, but for whatever it's worth, Abdullah has looked like Detroit's best rusher with Joique Bell still out. He's smooth in his breaks, and his first- and second-step acceleration is plus-plus. He just looks comfortable, which you can't always say about a rookie tailback. Again, at this level, where everyone is fast and physical, the true hallmarks of a good rusher are vision and tackle-breaking ability, neither of which can be seen until the pads come on. But you have to like the early returns from the second-round pick.
Most scouts seem to agree that Abdullah doesn’t project to be an every-down back, so Joique Bell’s between-the-tackles role should be safe, at least for this season. On the other hand, Theo Riddick’s role as the Lions’ third-down back is in serious jeopardy. With a small early-down role and significant time on passing downs, Abdullah could ultimately post top 25 numbers in PPR formats. He has upside from there if he's able to bite into Bell's workload.