Among the many surprises the 2013 NFL season had in store for us, Knowshon Moreno was one of the most shocking. After never producing more than 1,160 scrimmage yards in any of his first four NFL campaigns, Moreno logged 1,586 last year while scoring 13 TDs and becoming fantasy's No. 5 RB.

It's important to remember that last summer, both Moreno and Willis McGahee were presumed to be on their way out of Denver, as Montee Ball and Ronnie Hillman were supposedly going to vie for backfield work. Moreno missed last year's OTAs with a knee problem and looked like a possible roster casualty, but then Hillman kept fumbling in the preseason and Ball couldn't pass-protect. Give the Denver Broncos credit: They kept Moreno around and diagnosed a solution to their problem early. Moreno started Week 1 and never looked back.

But it speaks volumes about a player when the team he helped lead to the Super Bowl is utterly uninterested in re-signing him.

Knowshon Moreno will have a hard time approaching the career-best numbers he put up in 2013. AAron Ontiveroz/The Denver Post/Getty Images

So in 2014, Moreno will head to the Miami Dolphins, with whom he signed a one-year deal Thursday. When evaluating any player, we need to keep two things in mind: his talent and his opportunity. The opportunity in Miami is a big one. At 212 pounds, Dolphins RB Lamar Miller runs the 40 in 4.40, but being good isn't just about speed. Last year, Miller had a mere four runs that went for more than 20 yards (and he fumbled at the end of one of them) because he's not laterally instinctive and hasn't shown that he likes contact. Moreno will be 27 in July, and he doesn't have anything approximating Miller's raw speed, but he's an upgrade as a pass-blocker and is a proven tough guy. There's no question Moreno should be considered the favorite to lead the Fins in backfield touches, at least until he gets hurt. (Remember, Moreno missed 17 out of 32 games in 2011 and '12.) Dolphins RB Daniel Thomas, who has proved he has no lateral agility whatsoever and has also had concussion issues, could find himself on the roster bubble this summer.

So the opportunity is there, but is Moreno talented enough to make a big splash? I have my doubts. Of his 241 carries last season, 192 came with six men in the box or fewer. That's incredible! Moreno was 13th in carries among RBs overall, and 53rd in carries with seven defenders or more in the box! When I review his film, I see Moreno get through to the second level again and again without being touched, as defenses wore their terror of Peyton Manning on their sleeves. I agree that the Dolphins' offensive line will probably be better this year, and heck, maybe it'll even approach the quality in Denver. But no matter how exciting you find QB Ryan Tannehill, defenses won't be afraid to stack the box against Moreno when necessary. Plus, there's a reason Moreno has occasionally been called (by me, at least) "Slow-shon." Knee injuries have sapped his acceleration. In Miami, he'll have to rely on guile and power more than speed and open spaces, and as a fantasy back, he's going to remember his days in Denver fondly. I currently rank him 25th in my RB ranks, while Miller falls to 37th.

As for what's left behind in Denver, get excited for the Montee Ball era. I believe Hillman has proved during his first two seasons that he's not big enough to handle early-down work, and if he can't hold on to the ball and improve in pass protection, he won't play much on third down, either. C.J. Anderson flashed a bit toward the end of '13 and could participate as a backup, but he won't be given a big workload early. Ball is capable of receiving at least as well as Moreno (who was sixth in catches among all RBs last year, with 60) and packs a similar punch near the goal line. Will the Broncos threaten league records for scoring and yardage again this year? As my friend and colleague KC Joyner argues, perhaps not. But if Ball has figured out Denver's pass-blocking schemes, the opportunity is there for him to take at least nearly the same quantum leap Moreno enjoyed in '13. Right now, he's my No. 14 RB.