Daily Focus: How Arian Foster fits in Miami's offense

Editor’s note: Every day in “Daily Focus,” PFF analysts take the latest NFL news and translate what it really means for each team involved.

How Arian Foster fits in Miami's offense: After a second visit, the pen was finally put to paper, and the Miami Dolphins have a new running back. Foster's addition immediately throws doubt on the prospects of Jay Ajayi, who was the presumed starter after Lamar Miller left town for Houston.

The obvious elephant in the room with Foster is injuries. Even if he does get installed above Ajayi on the depth chart, how long will he last there? In seven NFL seasons Foster has started 16 games only once, back in 2012, and he has 26 games worth of missed time over the last five years, 20 of them in the past three.

In terms of fit within new Dolphins head coach Adam Gase’s system, Foster actually makes a lot of sense. He is a naturally smooth and gliding runner with an easy one-cut style that makes him a perfect match for the kind of zone plays that Miami will be running this season.

In Chicago, Gase ran primarily inside zone as the primary run concept. 48.9 percent of the team’s rushes last season were inside zone runs, and the team was pretty successful running them, averaging 4.2 yards per carry. Foster was bad across the board last year even before injury shut him down, but what is interesting is that Ajayi outperformed not just Foster, but also the Bears as a team when running inside zone. Ajayi gained half a yard more per carry than the Bears and 1.6 yards per carry more than Foster running inside zone plays, and was markedly more productive on those runs than other concepts in 2015.

Assuming Foster gets back to form not from 2015, he should be a solid fit in that scheme as well, but Ajayi’s numbers suggest he might be an even better fit, and shouldn’t automatically get dropped down the depth chart to accommodate Foster.

Can Eddie Lacy be one of the NFL's best backs in 2016? Green Bay RB Lacy was overweight last season. That’s no surprise to anybody with the power of sight, as even for a back with a relatively solid build he was visibly larger and slower last season. But the lengths to which he’s going to in order to resolve the issue are interesting.

Lacy hasn’t just spent his offseason doing P90X, but has actually been training with the founder, Tony Horton, leading to him showing up to the team’s offseason workout program down around 15 pounds from the season before. He’s recently been back for a Horton refresher course before the hard work of training camp starts, begging the question: What if we get the 2014 Eddie Lacy back?

That season Lacy was the third-best-graded running back in football, trailing only Marshawn Lynch and Le’Veon Bell, either of whom had a case as the best back in the game that year. Lacy was second in our elusive rating metric, thanks to breaking 49 tackles in the run game and 24 more as a receiver. The 2.82 yards after contact he averaged was third in the league, and only Lynch breaking 101 tackles – the most we have ever seen over a season – kept him out of the top spot in the elusive rating.

That year Lacy graded well in every facet of the game PFF measures, having had a very good rushing grade as a rookie, and looked well on his way to being one of the best backs in the league before his 2015 setback. If we get that player back in 2016, not only will we see one of the league’s best back on the field, but the Packers' offense will be a lot more formidable again on offense.

(PFF Fantasy Insight: Between Foster and Lacy, there are plenty of fantasy takeaways. Dan Schneier thinks Lacy's conditioning is one of the top fantasy situations to monitor in training camps. Meanwhile, Jeff Ratcliffe says Foster's impact with Miami will be more in the passing game, so Jay Ajayi should still hold some value.)

What Reggie Bush could bring to Bills: With Karlos Williams suspended and Jonathan Williams arrested last week, the Bills have extended an offer to Bush, according to NFL Network’s Ian Rapoport. Looking back at Bush’s career you can’t help get a sense of unfulfilled potential. He was unfortunate enough to draw Barry Sanders comparisons as a prospect coming out of USC, but in truth his best position in the NFL may have been as a slot receiver — an opportunity he was rarely given by the teams he played for.

Over his career, Bush has posted a positive grade as a runner just once over a season, and that was in 2014 when he only carried the ball 84 times. As a receiver, though, he has four such seasons, and when you look back to his early years in New Orleans you see some legitimate play split out as a receiver. During his rookie year, in 2006 (a season that PFF just finished grading retroactively), he lined up in the slot on 120 snaps, out as a wideout on 121 more, and posted career highs in targets, catches, receiving yards, average per catch and forced missed tackles as a receiver — as well as posting the longest catch of his career, an 88-yard wheel route that left the Bears looking ridiculous in the NFC Championship game.

Bush has only played 351 snaps over the past two seasons, and may be little beyond a camp body for the Bills if he signs, but in grading 2006 games over this offseason you get sight of an exciting athletic talent that may have had a far better career if he entered the league today.