Fantasy football owners should always approach running backs with caution. Even franchise ball-carriers still play the most vulnerable position in the league, and their season can be severely altered for any number of reasons.
This year's top fantasy backs—and overall players—are Arian Foster, Ray Rice and LeSean McCoy. Everyone has their own preferred order among those three, but you won't find many people who don't see them as the top-three fantasy picks this season.
They should be viewed like that, but fatal flaws still loom as potential pitfalls for these three players this season.
Let's take a look at each player and what could spell their downfall in 2012.
Flaw: Ben Tate
These two players coexisted last season, but while Foster was on the shelf for three games Tate was showing off his own ability.
Preservation is very much a part of every NFL team's run game. As good as Foster is, Tate is going to take touches away from him this season.
Last year, Tate had nearly 1,000 yards on 175 carries. He would start for most other teams, and Houston will use him as another cog in its offense this season.
Foster's ability to catch the football (53 catches last year) negates some of this impact, but it still has an effect on his fantasy production. Every touch that Tate gets is one fewer chance that fantasy owners have to cash in.
If you want to talk pure talent, Foster has it all. But Tate's emergence makes his situation interesting. He's a franchise back who may be forced to share the ball with another player, regardless of how he's playing.
The Texans know they need him healthy, and that will take precedence.
McCoy gets the ball a lot. He touched the ball 321 times last season, and that number isn't going to get any lower this season.
You have to wonder how much his smallish frame can take. He's not built like Rice or Adrian Peterson. He relies on his exceptional feet and agility in the open field, but he takes a lot of punishment.
I'll also mention Michael Vick here. Vick hasn't played in 16 games since 2006. Nick Foles has played extremely well this preseason, but who do you think defenses will focus on if Vick does go down?
Shady is one of the league's most exciting players, and his versatility is apparent every week, but I see him as the opposite of Foster. He needs someone to share the work with because sooner or later the workload will be too much.
McCoy has missed one game in each of the past two seasons, but that number could be more this season. The Eagles will have to be careful not to overwork him, but defenses will be focusing on McCoy this season.
Flaw: Loss of Ben Grubbs
You may think the Saints paid too much for Grubbs, but he was a big part of Baltimore's run game last year. The Ravens still have a very good offensive line, but depth could become a concern.
If running backs are the league's most vulnerable players, offensive linemen aren't far behind. Baltimore's starting five are all road graders, but look at the players behind them. Guys like Cord Howard, Tony Wragge and Jah Reid aren't going to do the job in the rugged AFC North.
Rice is, undoubtedly, the focal point of the Ravens' offense. He had 367 touches last season, and the Ravens' offensive front must be ready to push the pile at least that much again this season.
Admittedly, finding a flaw in Rice's game, or any of these backs' game, is tough. However, when you spend a top-three pick on a player, you have to look at any possible crack.
Losing Grubbs may go unnoticed, but his massive presence could be missed in front of Rice.