When Reggie Bush took his shifty outside running game to Detroit, the focus in Miami immediately turned to Lamar Miller. Well, that’s sort of a lie.

You see, while Bush was still doing swell things last year and chugging along for 1,278 total yards from scrimmage, the long-term focus had already shifted. It was just a matter of where it was shifting to, and for fantasy purposes beyond the 2012 season, that was a vital question.

Over the past two years, the Dolphins have invested two picks in running backs, one that was high, and one that was still reasonably high. Daniel Thomas was selected in the second round during the 2011 draft, and then last spring general manager Jeff Ireland followed that up with Lamar Miller in the fourth round. That’s when Bush surely realized that his time chasing anything that looks like a Kardashian in South Beach was drawing to a close rapidly.

Last fall, believing that Thomas would then inherit the starting job when Bush eventually left for his snow globe was safe thinking. Of course, that disregarded his severe lack of durability, as Thomas has missed five games over his two seasons. An easily combustible running back is less than desirable.

Then the cries were heard: bring us Lamar Miller, said the people, mostly us fantasy fiends hoping for a mid-to-late round bargain play. Judging by the public comments made since the Bush signing and the reports from Phins beat writers, magic genies keep granting us that glorious wish, and delivering fantastic news.

After Bush’s signing in Detroit, there was never much doubt that Miller would ascend the depth chart. What’s nice, though, is that Miller’s status as the featured back and the backfield leader behind Ryan Tannehill in an offense that just inherited Mike Wallace, Brandon Gibson, and Dustin Keller is continually being reinforced.

First, there was an encouraging comment from Dolphins head coach Joe Philbin regarding a crucial and sometimes overlooked running back skill, at least in the fantasy community: pass blocking. That’s an area where young running backs often struggle, and it’s partly what kept David Wilson chained to the Giants’ sideline throughout the first half of last season.

But Philbin isn’t too worried about Miller in the backfield on key passing downs:

“The last game of the year against the Patriots, there’s a good picture of him in blitz pickup, a real nice picture of him picking up, I want to say it was (Jerod) Mayo I believe if I’m not mistaken or (Brandon) Spikes. I can’t remember exactly. When you’re a running back and you’re going to throw the ball and you’re involved in protection, you’ve got to display the ability to pick up a blitzing linebacker even though it might be a mismatch from a size standpoint. I think he can do that.”

Trust. It’s still a great thing.

The most basic math tells us that the more a running back can stay on the field, the more opportunities he’ll have to make plays and contribute to your fantasy bottom line. Every yard, and every point counts, and if Miller has to be consistently yanked on passing downs, that opens the door for a platoon situation. Avoiding that also means avoiding partial fantasy death.

It gets better. In his post-free agency and pre-draft Dolphins roster breakdown, Omar Kelly of the South Florida Sun-Sentinel dropped this extra piece of awesome:

The Dolphins are concerned about Thomas’ durability, and his ability to be the big, physical goal line runner this offense needs.

Even when he was in a partial split with Bush last year, the Dolphin’s lack of confidence in Thomas as a goal-line bruiser was evident. Despite Bush’s more diminutive status by comparison, the Dolphins scored 10 rushing touchdowns last year, and none of them came when Thomas had the ball in his hands. That despite Thomas’ 165 carries, which was 62 carries behind Bush, a narrow distance over the course of an entire season.

That escalates Miller’s production potential further after we add more scoring potential to his quick burst through the hole which led to 4.9 yards per carry on his minimal touches in 2012 (51 carries). Keep that miniscule usage in mind again when you look up Miller’s chunk yardage, and see that he had three carries of 15 yards or more, including a 28 yarder. He has quicks, as the kids say. Or maybe I made that up entirely.

Unless the Dolphins target another running back early during the draft in a few weeks (quite possible), Miller’s fantasy value will continue to rise, and he’ll join Isaiah Pead among the top late-round backs with great flex or low-end RB2 value.