You might think that everything has been hunky dory in the fantasy football world so far this season, with quarterbacks routinely throwing for 300 yards and receivers galloping down the field unbothered as defensive backs lie helpless in their wake. Those owners who drafted Arian Foster, Chris Johnson, or Jamaal Charles in the first round might not have such a rosy worldview.

They don’t want to hear about aerial fireworks. They need to find some answers at running back.

Although Foster and Johnson will likely come around (even if the idea of Foster playing Sunday in New Orleans is doubtful at best), some quick fixes might be needed elsewhere. With that in mind, here are five guys who, depending on the depth of your respective leagues, just might be available as free agents and, even better yet, might be able to effectively fill starting fantasy backfield roles before you know it.

Daniel Thomas, Miami: This is the obvious one, and chances are he’s likely already on somebody’s roster. Still, there’s an outside chance that someone dropped him after hearing reports that the rookie from Kansas State was banged up and struggling with the pro game.

All of that looks like it’s in the past, considering he rumbled for more than 100 yards in a loss to Houston last Sunday and carried twice as much as Reggie Bush. He is the bell cow from this point forward for the Dolphins. Grab him if you’ve got any shot at him.

Roy Helu, Washington: Tim Hightower has been solid but unspectacular in the first two games for the Redskins, and his track record doesn’t suggest a guy who can keep a starting job the whole season. Helu hardly played in the opener, but he averaged more than seven yards a pop on 10 carries in a win against Arizona, a much more productive rate than Hightower.

If he does get in the lineup full time, remember that Mike Shanahan has a habit of turning unknown runners into big-time fantasy stars. Helu could just be the latest in that long line.

Dexter McCluster, Kansas City: This recommendation comes with a caveat. Even though McCluster is playing primarily running back, he is still listed as a wide receiver on the Chiefs roster. That could be problematic for you if you pick him to fill a hole at running back, so check your league commissioner before proceeding.

McCluster is a big-play waiting to happen, and although he’ll likely split carries with graybeard Thomas Jones, he can get a bunch of yards, and scores, with just a few touches. He could slide into Charles’ role and be a nice surprise from this point.

Keiland Williams, Detroit: OK, this might seem like a bit of a reach, but hear me out. Williams, who was signed by the Lions right before the season, was inactive Week One, but he quickly moved up to number two on the depth chart, picking up a garbage touchdown in the win over Kansas City.

When he got the chance last year in Washington, he produced as a runner and receiver. He simply got caught up in a numbers game with the Skins, but in Detroit, as a touchdowns vulture and a possible replacement for the always-brittle Jahvid Best, he just might have fallen into a perfect situation.

DeMarco Murray, Dallas: After two games of mediocre production, Felix Jones is already banged up. Meanwhile, Murray saw a little bit more time in Week Two, and he wasn’t chosen so high in the draft for nothing.

He has explosive ability, sort of like what Jones used to flash before he suddenly seemed to bog down once he got the starting job. Although veteran Tashard Choice will likely help out, Murray should be the top guy if Jones is out for any significant amount of time. And even if he isn’t, I still foresee the rookie taking the job sooner rather than later.

Most of these guys will likely take a few weeks to be factors, but owners desperate for running back help should take what they can get. It’s a long season, and I’m betting at least three of these guys will be worthy of fantasy starting status on a regular basis by the midpoint of 2011.