12 fantasy waiver-wire gems to pick up before Week 1

At long last, the NFL season is finally upon us. We're days away from real, meaningful football once again gracing our television screens and I couldn't be more excited. We've also entered the part of the year where all of our offseason study and preparation comes into play in fantasy. We've completed our drafts and are now faced with the task of setting a Week 1 lineup and fortifying our rosters for the initial gauntlet of the fantasy season. That's where the Week 1 waiver wire comes into play. This is our last chance to scoop up potential breakout players before they start producing on the field and the competition to acquire their services becomes significantly harder. With that in mind, I've highlighted 12 players below with relatively low ownership percentages across NFL.com fantasy leagues at this point. If you're looking for some sneaky Week 1 plays or to build up depth on your bench, target these players with vigor before Week 1 unfolds.

Dak Prescott, QB, Dallas Cowboys - 26.9 percent

Dak was a fun watch in the preseason while he was making splash plays each week, but he became one of the biggest stories of the NFL season when Tony Romo suffered a compression fracture in his vertebrae in Week 3 of the preseason. Prescott is the starter now for the Dallas Cowboys and  deserves our fantasy attention.

Yes, it's preseason, but Prescott's performance is encouraging. He completed 39 of 50 attempts (78 percent) for 454 yards (for a stellar 9.08 yards per attempt average) with five touchdowns and no interceptions. He also added 53 yards and two touchdowns on the ground. Prescott was quite the runner in college (averaged 801 rushing yards per year over his last three seasons), but it'll be interesting to see how often Dallas deploys him as a rusher. They did some read-option plays with Prescott and Zeke in the preseason, but with Dak as their starter now I wonder how often they'll want to subject him to unnecessary hits. In the end, Prescott plays behind a high-end offensive line with an elite wide receiver, reliable tight end, and a talented rookie running back in his arsenal. He should be able to post solid totals, with his rushing ability increasing his weekly floor and ceiling. If he continues playing and improving as he has thus far, he could be a difference-maker in fantasy.

Joe Flacco, QB, Baltimore Ravens - 8.7 percent owned

There are obvious injury concerns with Flacco as he works his way back from a torn ACL suffered in Week 11 of last season. That doesn't make it any less shocking that he's owned in so few leagues. His offense has been restocked with healthy, interesting weapons, though the loss of Benjamin Watson hurts a bit. Still, the addition of Mike Wallace as a true deep threat, the emergence of Kamar Aiken as a reliable possession receiver, and the healthy return of possibly both Steve Smith and Breshad Perriman gives Flacco more options than he ever had last year. Marc Trestman offenses average an eighth place finish in pass attempts, giving Flacco plenty of volume. The Ravens defense is also a far cry from the dominant units of old, which could put him into a lot of shootouts. All told, if Flacco stays healthy he could be in line for one heck of a statistical bounce-back year.

Spencer Ware, RB, Kansas City Chiefs - 14.0 percent owned

Despite his hype-train building up dangerous levels of speed in recent weeks, Spencer Ware's ownership percentage is shockingly low. He was one of my deep sleepers a few weeks back thanks to his explosive ability (5.6 yards per carry, 12.5 percent of carries went for 10-plus yards), and goal-line prowess (scored on five of his seven carries inside the 5-yard line). However, with reports swirling that Jamaal Charles might not start (or even play in) Week 1, Ware just became that much more valuable. If your draft is completed and he's somehow still on the waiver wire, add him immediately. If you're still prepping for your draft, Ware should be taken in the middle rounds. And if you're worried about taking him that early, just know his combination of efficiency and big-play ability rivaled David Johnson in 2015.

Darren Sproles, RB, Philadelphia Eagles - 12.6 percent owned

I also included Darren Sproles in my deep sleepers list along with Ware, but the buzz around the 33-year-old jitterbug continues to build as we approach the season. Offensive coordinator Frank Reich -- who was in San Diego last season when Danny Woodhead led all backs in targets (106) and receptions (80, tied with Theo Riddick) -- keeps asking his staff how they can put the ball in Sproles' hands more often. With the oft-injured Ryan Mathews as the leading back, it makes sense why the team would want to keep him fresh and healthy by mixing in a heavy dose of Sproles. DeMarco Murray and his 237 touches from 2015 left this offseason, and the team will likely split those evenly between Mathews and Sproles, giving the little speedster a workload that merits fantasy attention. Add in the fact that the Philadelphia will be starting rookie Carson Wentz under center who could be looking for a lot of checkdowns, and this season sets up nicely for Sproles to return to fantasy relevance. He could return to the 70-80 catch range he saw in his final years in New Orleans. He's a must-own in PPR formats, but could offer weekly flex appeal in standard formats as well.

Rob Kelley, RB, Washington Redskins - 0.2 percent owned

With Matt Jones (shoulder) on the shelf until the regular season and seventh-rounder Keith Marshall (elbow) on IR, undrafted rookie Rob Kelley made the most of his opportunities this preseason (38 carries, 198 rush yards, 5.2 ypc average), and likely sealed himself not only a roster spot, but potentially a larger role in this backfield in the regular season. Jones' rookie season was largely forgettable aside from his Week 2 explosion and case of fumbilitis, but his ADP kept soaring all offseason. That was until he suffered his shoulder injury and his ADP corrected. He is dealing with an AC joint sprain, an injury that can linger (just ask Randall Cobb last year). While Kelley was running mostly against backups in the preseason, he flashes the feet, vision, and finishing ability of a starting-caliber NFL back. His one downside is a lack of breakaway speed (4.68 40-yard dash), but he can still be a productive fantasy rusher without that. Kelley's drumbeat around the organization has been building for awhile now, with some even positing that he should be the Week 1 starter. Whether or not Kelley actually earns meaningful snaps in the regular season remains to be seen, but his ability and the uncertainty surrounding this backfield make him well worth a pickup before the season officially starts. If he doesn't get work, he'll be an easy drop. But if he does show up and start producing, he'll be a lot harder to pick up once EVERYONE sees him do it in the regular season. Be ahead of the curve and grab him now if you can.

Jerick McKinnon, RB, Minnesota Vikings - 14.9 percent owned

After a strong preseason and countless offseason reports of an expanded role, Jerick McKinnon looks like a perfect late-round flier or pre-Week 1 waiver add. He could have weekly value as a pass-catching back while the Vikings try to keep Adrian Peterson fresh, especially now that Teddy Bridgewater has been lost for the season and the team traded for Sam Bradford. McKinnon is more dynamic in space than Peterson and a more natural pass-catcher. If the Vikings fall behind more often or are in more competitive games due to poor quarterback play, McKinnon could be the primary beneficiary. And in the event that Peterson were to suffer any sort of injury, McKinnon would jump to weekly-RB1 status. He's that talented.

Mike Wallace, WR, Baltimore Ravens - 21.0 percent owned

Much like with the Flacco section, Mike Wallace is being a little too ignored in fantasy circles for my liking. I understand the trepidation, though -- I've honestly never been a huge Wallace fan -- as this is his third team in as many seasons. Still, Wallace's skill as a deep threat fills a much-needed role in the Ravens' offense, and if early reports are to be believed he and Joe Flacco are already boasting a solid rapport. Wallace isn't going to win any leagues, but as a late-round fourth or fifth option at the position, his upside in a pass-happy offense is extremely tantalizing.

Will Fuller, WR, Houston Texans - 7.4 percent owned

When the Texans drafted Will Fuller in the first round back in May, I thought the move was a better football than fantasy football pick. Fuller would offer them the speed they desperately needed, but I had questions about how quickly Fuller would transition to the NFL game, and what type of volume he'd see in Houston. After watching Fuller in the preseason, many of my concerns have been assuaged (although his hands are still a question mark), making Fuller an interesting post-draft add. He's shown a good rapport with Brock Osweiler and seems to have a firm grasp of the offense, as well as strong ability as a route-runner. At worst, he's worth grabbing before his Week 1 contest against a Bears defense that could be missing three of their starting corners. If he goes off for a big game then, he'll be much harder to win off of the waiver wire.

Tajae Sharpe, WR, Tennessee Titans - 6.5 percent owned

All offseason the Titans showered praise on Tajae Sharpe, and we took it with a grain of salt. However, after they shipped Dorial Green-Beckham off to Philly and anointed Sharpe as one of their starting wide receivers, it was time to take notice. Sharpe is a meticulous route-runner who has the trust of his quarterback, Marcus Mariota, and a starting role in what could be a sneakily good offense. He should see anywhere from 100-120 targets, making him very relevant in fantasy. If he went undrafted in your league, rectify that mistake immediately.

Kenny Stills, WR, Miami Dolphins - 1.8 percent owned

While DeVante Parker was the offseason darling of many fantasy analysts, he's looking more and more like a mirage. He's a talented player, but one who might be fighting for a more regular role in the Miami offense. That's because Jarvis Landry is still around as a target vacuum, and Kenny Stills has looked like a more competent and reliable No. 2 option than Parker. Stills showed up well in the preseason (eight catches, 124 yards, two touchdowns in three games), and looks to have settled in nicely in Adam Gase's system. Let's not forget Stills was showing progress as a route-runner and tactician back in New Orleans before the team traded him to the Dolphins. His volume may still be spotty at times, but he's worth an add heading into Week 1 based on the head of steam he's built up.

Jared Cook, TE, Green Bay Packers - 18.5 percent owned

I know, I know. We've been waiting for Jared Cook to realize his potential for years and he's continually let us down. Why buy in now? One simple reason: Aaron Rodgers. Last year, Richard Rodgers averaged a measly six yards per target in Green Bay with Aaron. In Cook's career catching passes from the likes of Jake Locker, Rusty Smith, Nick Foles, Sam Bradford et al, he averages 7.4 yards per target. He's the strongest candidate to emerge as the No. 3 pass-catching option in Green Bay behind Jordy Nelson and Randall Cobb. In the Packers' high-octane offense, that's a role fantasy owners want a part of. It'd be a shock if Cook doesn't finish the year as a top-10 tight end, so don't let him sit on the waiver wire any longer.

Virgil Green, TE, Denver Broncos - 2.4 percent owned

Virgil Green, like Cook, has been a trendy "breakout" for years because of his athleticism. He's yet to deliver, but with Owen Daniels out of the picture, this could be the year. Green demonstrated a solid connection with Trevor Siemian in the preseason and looks to have the starting tight end job locked up ahead of Jeff Heuerman. The tight end position in a Gary Kubiak offense has been good to fantasy players over the years, and Green could be the next in line. He's worth an add in deeper leagues, or at least worth monitoring in more standard formats in case he finally does begin that breakout candidate.

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-- Follow Alex on Twitter @AlexGelhar