Everyone in their Fantasy league who had the No. 1 overall pick this year was likely giddy. You had the chance to pick the best player in the league, and for the most part there was one clear-cut choice -- Cardinals running back David Johnson.

Unlike Le'Veon Bell or Ezekiel Elliott, Johnson came with little baggage. There wasn't a holdout or a potential suspension keeping him off the field. He was going to be an absolute workhorse. Only an injury could ruin things for Johnson.

And here we are.

One week into the season, Johnson is out for at least the next eight weeks with a wrist injury after getting hurt in the season-opener at Detroit on Sunday. Johnson will undergo surgery to repair the wrist, and ESPN reports he will be out 2-3 months while recovering. He has been placed on injured reserve.

Johnson is eligible to return later this season when healthy, but by that point, your Fantasy season might be over. This is a huge blow for Johnson and the Cardinals, as well as for Fantasy players.

"It's always a huge blow to lose a top player," Arians said Monday at a news conference. "But it's not the end of the world. It's an opportunity for someone to step up. David Johnson became David Johnson because of somebody's injury."

The Cardinals have already signed running back D.J. Foster off New England's practice squad for depth, and the team could still bring back free agent Chris Johnson, who was released during the final cuts before the season and has spent time with Arizona in recent years. Most likely, the Cardinals would replace Johnson with a committee of Kerwynn Williams and Andre Ellington.

Williams, who is owned in 9 percent of leagues on CBS Sports, is the Cardinals running back to target off waivers. He finished the game against the Lions with five carries for 10 yards and a touchdown, and one catch for 2 yards.

Last year in Week 17, Johnson injured his knee against the Rams, and Williams had 12 carries for 60 yards and a touchdown in relief. We hope that's the role Williams will play now in Johnson's absence, but don't break the bank for Williams on waivers. He'll be the No. 3 running back to add this week, once my waiver-wire rankings come out.

Ellington will likely work on passing downs for the Cardinals, and he could also get the chance for carries. Once a starting running back for Arizona in 2013 and 2014, he was briefly moved to receiver this offseason, before going back to his natural position.

Injuries have plagued Ellington during his career, but he can work in tandem with Williams as the No. 2 option until and if Johnson returns. He's worth adding in deeper leagues, and his ownership is at 1 percent on CBS Sports. He had no carries and two catches for 35 yards against the Lions.

The good news for the Cardinals this week is they face the Colts, who looked awful in Week 1 at the Rams in a 46-9 loss. But while Todd Gurley had 15 Fantasy points in a standard league, he didn't run well, finishing with 19 carries for 40 yards and a touchdown. He was saved with the touchdown and his receiving production at five catches for 56 yards since he averaged just 2.1 yards per carry.

For this week, consider Williams a No. 2 running back, and Ellington just a flier. This is a game where the Cardinals should dominate time of possession, and Williams has the chance for a decent workload.

Aside from the Cardinals backups, Johnson owners looking for replacement options off waivers can target Tarik Cohen (28 percent ownership), Javorius "Buck" Allen (2 percent), Chris Carson (22 percent) and Marlon Mack (41 percent). 

In ranking the running backs to add this week, go with Cohen, Allen, Williams, Carson, Mack and Ellington, in that order. Plan to spend at least 20 percent of your FAAB dollars on Cohen and Allen and at least 15 percent on Williams. Carson and Mack should go for at least 10 percent, and Ellington is only worth about 5 percent at best. But also know the history of your league and how much players typically go for.   

Tarik Cohen
NYJ • RB • #31
OWNED30%
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Cohen just had five carries for 66 yards and eight catches for 47 yards and a touchdown against the Falcons in Week 1, and he will continue to share playing time with Jordan Howard. Also, given the injuries to Chicago's receivers -- Cameron Meredith (knee) and Kevin White (collarbone) are out for the season -- Cohen will be a huge factor in the passing game. Cohen could be a great option in PPR leagues.

Javorius Allen
NYG • RB • #37
OWNED3%
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Allen now has plenty of upside with Danny Woodhead (hamstring) being lost for an extended period of time. Allen will share playing time with Terrance West, and Allen just had 21 carries for 71 yards against the Bengals in a blowout victory in Week 1.

West will remain the starter and had 19 carries for 80 yards and a touchdown against Cincinnati, but he and Allen could once again do damage in Week 2 against the Browns at home. Allen also should be a solid running back in PPR.

Chris Carson
SEA • RB • #32
OWNED22%
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Carson, with Thomas Rawls (ankle) out in Week 1, was Seattle's best running back in a loss at Green Bay with six carries for 39 yards and one catch for 10 yards. Rawls is expected to return in Week 2, which ruins a potential dream matchup for Carson against San Francisco. But Carson is clearly the No. 2 running back for the Seahawks ahead of Eddie Lacy and C.J. Prosise and is worth stashing, especially given Rawls' injury history.

Marlon Mack
ARI • RB • #37
OWNED41%
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As for Mack, he's behind Frank Gore, but Mack was one of the few Fantasy bright spots for the Colts in Week 1 with 10 carries for 24 yards and a touchdown and one catch for 21 yards. Gore is 34, so a breakdown is always possible, and Mack looks like he's a significant part of this offense.

Along with the waiver wire, Johnson owners should be aggressive in making trades. If you have receiver, quarterback or tight end depth, you might want to buy low on the following running backs who struggled in Week 1, including DeMarco Murray, Ameer Abdullah, Rob Kelley, Bilal Powell, Tevin Coleman and Joe Mixon.

All of those guys had five Fantasy points or less in a standard league, and they might be available via trade for the right price. There are plenty of other running backs to consider as well, although none offer the upside of Johnson unless you're able to acquire someone like Bell or Elliott.

We hope the second opinion on Johnson brings us good news, but Arians made it sound like Johnson will miss significant time. He said "you've got to be smart. That can be a career-ending injury."

If Johnson does go on short-term injured reserve, the hope is when he does return he can be a dominant Fantasy running back to close the season. And then he can reward the Fantasy owners who drafted him at No. 1 overall.