Leonard Fournette, Jaguars
This one was inevitable since whatever team picked him would use him as its lead back, so "riser" might not be the best term, but he's firmly in the running for offensive rookie of the season with the workload he is likely to get. Unfortunately, Fournette won't have an offensive line like Ezekiel Elliot had coming into Dallas last season. Fournette will struggle in Jacksonville, but has the ability and opportunity to be a Top-10 back if lucky.
Joe Mixon, Bengals
Mixon landed in a great spot on a run-oriented team whose lead back, Jeremy Hill, is average at best. Additionally, Mixon is adept in the receiving game, so he could cut into Gio Bernard's workload as well. This landing spot puts Mixon near the top of dynasty rookie drafts.
C.J. Anderson, Broncos
Anderson managed to side step any early running back draft picks from the Broncos. They did end up grabbing De'Angelo Henderson in the sixth round, but he shouldn't be a threat to Anderson this season. Anderson, of course, will need to produce and stay healthy, but he should have the starting job secure heading into this year. Update: Jamaal Charles is visiting Denver. If he signs, C.J. would likely lose work to J.C.
Christian McCaffrey and Curtis Samuel, Panthers
The Panthers got two nice play-makers in the first two rounds of the 2017 NFL Draft, but McCaffrey is, of course, the top fantasy name here, especially at running back, as Samuel will most likely be converted to slot receiver.
The Panthers haven't thrown the ball to their running backs at all, but Mike Tolbert and Jonathan Stewart also led the team in targets for running backs over the last three seasons. The Panthers need a spark to this offense, and McCaffrey could be that. Add in Cam Newton's rushing ability, and McCaffrey should have plenty of room to work both in the rushing and receiving game.
Doug Martin, Bucs
The Buccaneers didn't take Dalvin Cook, which was a possibility, and waited until the fifth round to grab Jeremy McNichols. McNichols has some upside, but Martin should still be in line for the starting job once he returns from his suspension. There is some talk of him being released, but the news out of Tampa Bay's offseason program is that Martin looks great and most signs point to him staying with the team.
Samaje Perine, Redskins
Perine doesn't have a job as of yet, but he only needs to beat out Rob Kelley. The two have some similar ability, but Perine has shown more on tape than Kelley ever has. They both fit the run-blocking scheme in Washington, so really it comes down to Perine beating Kelley. That may or may not happen, but I believe Perine is a better back and, barring injury, should take over eventually.
Marlon Mack, Colts
Mack isn't an all-around talent like Frank Gore, but he's a big-play threat, which Gore just can't be at this point. If Mack had landed behind a steadier running back presence, I would likely have thrown him into the "good upside if he can ever find the field" pile, but the Colts are so deficient at the running back position that Mack has real upside this season.
Bilal Powell, Jets
The Jets didn't draft a running back until the fifth round, so their depth chart really is just Matt Forte and Powell. Forte may be considered the starter, but Powell was obviously the better back last season. They will continue to split carries, but Powell should continue to see more overall work and now won't have any young guns trying to get famous behind him.
Chris Ivory, Jaguars
Ivory is a decent running back, but just can't stay healthy with his running style and was not helped by the Jaguars' blocking. Leonard Fournette may have similar trouble in the NFL with his hard-nosed approach, but he'll get his shot as the starter while Ivory could be released.
Jeremy Hill and Giovani Bernard, Bengals
Joe Mixon will hurt both these players' upsides no matter what, but could easily make them obsolete for fantasy. I doubt that happens with Bernard, but it is a possibility, as Mixon is strong as a receiver, and as long as he can pick up pass protection, he will likely be groomed as a three-down back.
Jonathan Stewart, Panthers
Stewart has gone from a top dynasty buy to a bottom-of-the-barrel sell in a relatively short time. Injuries and misuse have compiled, and now, McCaffrey is in to take away a big chunk of work. Stewart will still get work as an inside runner, but will lose some of that to McCaffrey and Newton, so I'm off Stewart completely for 2017.
Rob Kelley, Redskins
Kelley managed to bypass Dalvin Cook, who was reported as someone Washington wanted, but the organization did go ahead and grab Samaje Perine in the fourth round. I like Perine more than Kelley, but of course, Kelley has a year in the system and a head start. That being said, I don't see any reason Perine can't beat Kelley out as the starter at some point this season.
Frank Gore, Colts
Gore is still a steady back, but no longer has the ability to get more than he's given. After never falling below four-yards-per-carry in his career, Gore has averaged 3.7 and 3.9 yards per carry the last two seasons. The Colts love his pass blocking, but at some point, they must find some more offensive production out of the position, and at the very least, they'll give Marlon Mack a shot at taking carries away from Old Frank.
Dalvin Cook, Latavius Murray and Jerick McKinnon; Vikings
Cook could have been drafted into a much better situation, but Minnesota is one in which he can compete for starting reps early on. The Vikings severely miss Adrian Peterson's ability to make big runs from average blocking, and they're hoping Cook can do that quickly. Latavius Murray and Jerick McKinnon have shown some upside here and there, but they've also shown their limitations. Cook will get his chance to lead the way this season, but will likely share reps and won't be on a good rushing offense. I'd draft him in the right spot, but I doubt he falls to that spot.