It is Week 8, the fourth week of bye weeks, and some big names go on vacation this weekend, so run to the waiver wire for some much needed help. You need someone to step in and hold down the fort for a week, or maybe more in some cases.

WEEK 8 BYES: Atlanta, Chicago, Green Bay, New York Jets, Oakland, Tampa Bay

It's fantasy football bye weeks, folks, so everyone's going to be scrambling for some fill-in players because some of us have a tendency to draft our back-up without realizing he has the same bye week as our starter. Here are some of the best options available.

Some of the players listed in Athlon Sports' NFL Fantasy Football Waiver Wire Week 6 may be one-week adds, some may be season-long adds and some are listed just for you to keep an eye on to stash on your roster if you have the space.

Titans RB Chris Johnson

What is it with these AFC South running backs?

Is there one we can trust this year?

Tennessee's Chris Johnson ended his holdout by signing an extension with the Titans on Thursday.

Houston's Arian Foster is giving fantasy footballers everywhere heart palpitations after his Tweeting of an MRI of his right hamstring.

Jacksonville's Maurice Jones-Drew, easily in the conversation with Johnson and Adrian Peterson last year for which back to draft No. 1 overall, is pouting on the satellite airwaves of his own SiriusXM show that he doesn't understand why he has fallen so far on draft boards after issues with his knee all last season. It's because we haven't seen you all preseason, MJD. Hopefully that will change tonight in the final preseason game.

And then there are the Indianapolis Colts. What to do with this backfield? Do they even run enough for us to care as fantasy players? Can Joseph Addai stay healthy? Will Donald Brown ever live up to his first-round selection. Is Javarris James or rookie Delone Carter going to be the goal line back. Where does former Virginia Tech stud Darren Evans fit into the mix?

But back to the Johnson signing. It puts him squarely back into the conversation as one of the top four backs to select in your fantasy football drafts. Or does it?

I still have Foster pegged as No. 1 until we hear anything worse on his hamstring. If it's a tear, I drop him to 14th.

We still have Adrian Peterson ranked No. 2 because, well, because he's Adrian Peterson and he seems to get it done no matter how bad the Vikings are. If he does it again this year, he will be No. 1 forever.

Ray Rice sits at No. 3. And he could easily move to the No. 1 spot in all formats as he is the safest pick.

LeSean McCoy is ranked No. 4 by Athlon as our standard scoring system rewards half a point per reception. Have you watched the preseason? The Eagles' offensive line doesn't look any better, and McCoy is there to reap the rewards in the form of dump-off and check-down passes.

Jamaal Charles sits at No. 5 as the news of Dexter McCluster getting some action in the backfield along with Thomas Jones, Le'Ron McClain, a below-average QB in Matt Cassel and a brutal schedule, leaves people nervous about Charles.

Then there's CJ.

Word is that he will be more involved in the passing game this season, and if we knew that to be true he would be No. 4 in our rankings as a result. But he hasn't been in camp. Johnson hasn't practiced with new offensive coordinator Chris Palmer's playbook; he hasn't played with new QBs Matt Hasslebeck and Jake Locker.

What he also has not done is anything at game speed. And this is where we come full circle from yesterday. Arian Foster and his hamstring dominated the news. Will it get worse? Is it a tweak? Is it a tear? Will Chris Johnson's hamstring be the next to dominate the news cycle?

With veteran players and holdouts, new system or not, we are not as worried about how quickly they can learn, we are more worried about how healthy can they stay. There have been a few high-profile hamstring injuries in recent seasons after holdouts — New York Jets defensive back Darrelle Revis last season and Green Bay Packers running back Ryan Grant in 2008. Both were able to play the season, but they were injured nonetheless.

This is the biggest worry about CJ right now. He seemingly always trains on his own in Orlando in the offseason, and the numbers that has produced the last three seasons aren't too shabby.

If you are drafting today, tomorrow or even right up until the season kicks off a week from now, Chris Johnson is still a top-six RB pick. And monitor the news over the next week and see if he getting a lot of action in the passing game. Even if it's just a bit, I am moving him over Charles because Johnson has a clear path to all the carries (not too worried about Javon Ringer and Jamie Harper in the long run) and an easier schedule.

— Corby A. Yarbrough @AthlonCorby on Twitter