With most of the top-tier running backs going over the $50 mark, risk is what differentiates between a winning and losing season. One doesn't have to look too far down the list of top RBs to find some big risks. At No. 1, we have a player who's had one good year. Down the list, we have players coming off injuries, surgeries, and workloads that they've never dealt with before. If there's any silver lining here, it's that so many of the top backs are injury risks that they cancel each other out. Only three of the Top-10 backs miss my list and even those three have their own injury concerns. Adrian Peterson wasn't drafted high because of his collegiate problems. Ray Rice slipped on concerns about his size and how much workload he could handle. LeSean McCoy was on this list originally, but splitting time with Ronnie Brown is likely to keep him from taking enough carries to be a real risk, but it also hurts his fantasy value another way.
Arian Foster -- Texans (SI.com Rank: 1)RISK ADJUSTED RANK: No. 5
Since Foster injured himself on the first day of camp, it's an easier sell now telling you that he's a health risk. Foster had one of the more impressive seasons in fantasy history last year, running behind a solid line and playing off a passing game that kept teams from stacking the box against him. Scouts insist that Foster -- a guy who came into last year's camp as the RB3 behind Steve Slaton and Ben Tate -- is a system guy who's in the right place at the right time, not unlike Ryan Grant a few years back. That's not an insult. More important, he is still in that system, with the same people surrounding him the way that Grant had until his injury last season. Foster was a bit injury prone in college and has never had the workload he had last season. It wore on him, as he needed a minor knee cleanup in the offseason, but that's not much to worry about. The worry is that the surrounding cast might not stay as healthy or that the turf in Houston might claim another victim. There's even the risk that a now-healthy Tate/Slaton combo might take some carries, though that would be a health-positive, fantasy-negative move. Foster is good, maybe even great, but expecting a repeat performance with no track record is tough. Expecting it from a guy with a history of leg issues is tougher.
Jamaal Charles -- Chiefs (SI.com Rank: 3)RISK ADJUSTED RANK: No. 2
Don't mistake moving up on the risk-adjusted rankings as being without risk. Charles carries a lot of risk, especially if he, as expected, takes more of the split of carries from Thomas Jones. People seem to think of Charles as a small back, but he's solid, getting comps like Emmitt Smith and Fred Taylor when put through numberFire's projection system. Charles could go from 230 carries up to around the 300 mark if coach Todd Haley has his way. The risk goes up significantly for all backs at the 250 mark, then again at 300, so keeping him between those is a nice progression. Another factor in his favor is that not all carries are created equal. Scouts tell me that Charles went outside the tackles more often than most feature backs, leaving the hard runs inside the tackles to Jones. (If you have to ask why outside runs are less problematic, you haven't watched enough football. I wanted to check the scouts' assessment, but wasn't able to find that data publicly.) Charles isn't a pure speed back, so an increase in workload shouldn't be too much for him to take, making him perhaps the back to take if you have a top pick.
Chris Johnson -- Titans (SI.com Rank: 5)RISK ADJUSTED RANK: No. 4
I had a high school football coach who used to yell random catchphrases out, apropos of nothing that we saw. Then again, Bob Newton now has the field named after him in Homewood, Ala., so maybe we should have listened more closely. Newton would yell out "speed kills!" a lot, especially when someone broke containment and burned up the sideline. Johnson would have Coach Newton losing his voice, since Johnson is the purest of speed players. With no history of leg problems, Johnson is young enough and fast enough to keep this up. He hasn't been asked to do things he can't do, like drive through the line, though he can do it just enough to keep defenses honest. A new coaching staff should be able to see what Johnson can and can't do, though his holdout won't help things. Johnson's not as risky as many think, but like any speed player, he's one hamstring strain or torn ligament away from being near-worthless.
Rashard Mendenhall (385 carries) -- Steelers (SI.com Rank: 7)RISK ADJUSTED RANK: No. 7
The rule of 370 is often derided, but if it was less a rule and more a suggestion, I'd suggest that Mendenhall's 385 carries last season, including playoff games, might be a workload that would see some drop-off this season. Mendenhall was essentially healthy despite the workload. Mendenhall increases his value with his size (21 goal-line carries) and his pass-catching abilities, one of the few backs to do it all and not even have a real change-of-pace guy. He's either underrated or overworked. Drafting him at the top of the second tier protects you both ways.
Darren McFadden -- Raiders (SI.com Rank: 8)RISK ADJUSTED RANK: No. 17
McFadden is already out with a fractured orbital, an injury that is random in nature, but will clear up in a couple weeks and bring back the Eric Dickerson style goggles to the NFL. There's no question that McFadden is talented, as he showed last season. There were few players other than Michael Vick that put up the kind of peak numbers that McFadden did, but with that, you have to take the occasional zeros or handcuff Michael Bush to him. (Even that's not an ideal fantasy strategy.) McFadden is a risky guy who's best cast as an RB3, putting him in matchup weeks, but whose role and peak value makes him a high RB2. McFadden's workload is self-limiting and he's likely to miss three or four games and be essentially out of a couple more. If you insist on drafting him, wait until the later run on RBs, but then you have to play him any week he's healthy so that you don't kick yourself for missing out on a 40-point game.
Maurice Jones-Drew-- Jaguars (SI.com Rank: 9)RISK ADJUSTED RANK: No. 8
Jones-Drew ended the season on an operating table, but has been selling the story that he "played on one leg" for most of 2010. There's no way to know whether that's the case, but by the numbers, there wasn't much difference between his '09 (when he was allegedly healthy) and his '10 (when he allegedly wasn't.) Since the injury was relatively minor, but at least progressively worse over the last half of the season, it's better to look at the first half for his true talent level. The knee issue adds to the risk slightly, but many players and many similar RBs have come back from this with no issue. Remember -- this was not a ligament or stability issue, so any reports that it's a problem now are simply wrong. If you have a late draft, watch to see if Jones-Drew can cut and burst. If he can, draft him normally.
Frank Gore -- 49ers (SI.com Rank: 10)RISK ADJUSTED RANK: 18
Gore is the very definition of risk. He's always been productive during the times between his injuries, but as he ages, and without the help of a credible passing attack, his fantasy value has slid some. There's always someone who dreams of him as an upside play out of the RB2 slot, and yes, it's still there if you squint. Gore's hip injury nearly completes his set for possible leg injuries and may cost him some of the drive that's kept him functional despite the knee injuries. He's good when healthy, but you can't count on it. He's a nice RB2 (or better, RB3) who's going to go in the second round of most drafts. (Current ADP is 16 according to MockDraftCentral.com.) Let someone else take on the risk and grab a RB who's perhaps less regarded but can put up season-long production.
Ryan Mathews -- Chargers (SI.com Rank: 11)RISK ADJUSTED RANK: 21
The problem with Mathews is that all we know of him are the problems. Mathews couldn't stay healthy through his first NFL season. He broke down, healed slowly, then broke down again. It could be a fluke or it could be that he simply can't hold up to the forces and demands of the NFL game. With an ADP of 30, Mathews is simply ranked too high for an unproven back with proven injury risks. His drop puts him in an area where he's a upside pick, but with a toe injury already in camp, the chance of more injuries and missed time this year makes it hard to recommend Mathews at any valuation.
Mikel Leshoure -- Lions (SI.com Rank: 22)RISK ADJUSTED RANK: No. 22
Ignore the ratings above, since Leshoure is out for the season with a torn Achilles tendon. But his injury brings up another point. There have been nine Achilles tears so far in the first week-plus of training camps, but that's not actually a huge number. In '10, nine players tore their Achilles during camp. Leshoure was the ninth so far in '11, so while it's ahead of pace, it could be that this is right on target, assuming there's no more. It's not a safe assumption, though doctors and athletic trainers I have spoken with say that it's difficult to say that any change in routine or being "out of shape" would contribute to such a tear. There's not a great track record for players coming back from this, especially at running back. There's a 2010 study that says the expectation is to lose 50 percent of power. Lions fans can try to get a read off LenDale White, a physically similar player who's coming back this season. In '11, the Lions will have to hope that Jahvid Best can stay healthy.
Ryan Grant -- Packers (SI.com Rank: 27)RISK ADJUSTED RANK: No. 27
It's a bit odd that we have the big gap in injury risk from nine of the top 12 all the way down to Grant. That's not to say that guys in the middle are without risk, but that the worry is less. Felix Jones has been injury prone, but his carries have been limited, as have players like Fred Jackson and the Carolina backs. Reduced workload means reduced risk. That may affect Grant this year as he comes back from a fractured ankle that cost him almost the entire '10 season. Grant should be able to come back from his ankle injury, but the Packers now have options, such as James Starks. If Grant lost anything to the injury, even just confidence, then he's likely to lose carries. Grant was once a cheap option that worked in the system. Now he's a more expensive option, aging and post-injury. That's not a good combo in an NFL that lacks sentimentality. Don't make that mistake by drafting him like it's '09. In '11 he's a nice RB3 or Flex with some upside. His risk is a balance of new health, a new injury history, and the chance that he loses workload. It's a lot of factors that end up putting him right where he started.
(List is based on SI Rankings, as of the date of this article, and adjusted for risk based on that projection. This is not my suggestion for a draft list. I only go as deep as is necessary to get 10 interesting risk/injury cases.)
-- TIER ONE --
Adrian PetersonJamaal CharlesRay RiceChris JohnsonArian Foster
-- TIER TWO --
LeSean McCoyRashard MendenhallMaurice Jones-DrewSteven JacksonMatt ForteKnowshon MorenoShonn GreenePeyton Hillis
-- TIER THREE --
Daniel ThomasAhmad BradshawMichael TurnerDarren McFaddenFrank GoreFred JacksonFelix JonesRyan MathewsLeGarrette BlountMark IngramDeAngelo WilliamsJonathan StewartRyan Grant
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