It can be tempting to focus exclusively on the trade market this time of year, but it may also be your last chance to add a significant piece via the waiver wire. Sellers are especially likely to give different players playing time over the next few weeks, creating one last wave of worthwhile waiver pickups before the well dries up in August.

The Cincinnati Reds are clear sellers, and have already announced some roster changes ahead of the deadline. Pitcher Luis Castillo has been inserted into the team's rotation, generating buzz with a fastball averaging 97.8 mph. Scooter Gennett has also taken over for Jose Peraza as the team's regular option at second base. Will either player help fantasy owners down the stretch?

Ownership rates provided are from Yahoo leagues.

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The Fantasy Jury is Out

Luis Castillo (SP, CIN) 23% Owned

To be clear, this is not a career revival for the second baseman who famously dropped a pop-up to lose a game in the Subway Series. This is a young flamethrower whose electric stuff has generated a 3.86 ERA, 3.66 xFIP, and 29.5% K% in 35 IP. His 10.3% BB% suggests that he's still pretty raw, but a K% this high is worthy of fantasy attention regardless of the uniform it's in.

Castillo uses a basic three pitch mix. His heater generates whiffs at an above average rate (9.5% SwStr%) while also spending a healthy amount of time in the strike zone (53.6% Zone%), creating a solid foundation for his secondary pitches to work off of. His change is elite, offering a 22.6% SwStr%, 42.5% chase rate, and .114/.135/.200 triple slash line against. Castillo also features a slider with a 17.1% SwStr%, 39.7% chase rate, and .105/.105/.158 line against. Overall, this is the kind of stuff necessary to maintain a K% approaching 30%.

Castillo did not generate this many whiffs at Double-A, where he pitched 80 1/3 IP with a 25.6% K% before reaching the Show. His ERA (2.58) and xFIP (2.70) were both strong on the farm, and his K% is significantly higher than anything he did before. Castillo likely made an adjustment that allows him to better utilize his raw stuff this season, supporting optimism that he can continue to produce fantasy-relevant results.

Those results have thus far been hampered by a 21.2% HR/FB, but there is reason to believe that Castillo can cut that number significantly moving forward. He posted a 6.4% HR/FB at Double-A with similar numbers at other minor league stops, so fly balls were not always a huge problem for him. A whopping 21.8% of his fly balls were also pop-ups at Double-A, suggesting some skill in limiting hard contact. His MLB IFFB% is just 9.1% so far, but this could be a small sample fluke.

Castillo's Statcast data also suggests that his HR/FB is too high. His average airborne exit velocity against is around average at 92.8 mph, and batters have not been able to square him up at all with a 4.5% rate of Brls/BBE. Great American Ballpark and whatever has inflated homers around the league will likely keep Castillo's HR/FB a little on the inflated side, but he's not anywhere near as bad as his HR/FB would lead you to believe.

Castillo's .272 BABIP may seem lucky, and indeed there is no reason to believe that he can maintain his 6.8% LD%. However, the Reds currently lead baseball with 42 DRS as a unit. Catcher Tucker Barnhart (14 DRS), 3B Eugenio Suarez (seven), CF Billy Hamilton, and 1B Joey Votto (six each) all stand out as superlative defenders. Castillo hasn't seen much benefit from this yet, as both his .286 BABIP on ground balls and .833 mark on line drives are above league average. Castillo doesn't allow especially hard contact, so the defense behind him should mitigate the upcoming LD% regression.

It will be interesting to see if his additional liners come out of Castillo's GB% (55.7%) or FB% (37.5%), as fantasy owners would love for him to live on the ground in that park. The upside should be owned in more than 23% of formats regardless, likely by a team that needs to chase volatile upside in order to finish in the money. If that's you, you know what to do.

Verdict: Champ

 
Scooter Gennett (2B/3B/OF, CIN) 23% Owned

Gennett's four-HR game on June 6 put him in the national limelight, but his .308/.360/.585 line with 16 homers is indicative of more than one hot night. His 25% HR/FB probably won't hold as an everyday player (10.8% career), but this is a different guy than he was in Milwaukee.

For starters, Gennett's contact quality has improved dramatically relative to last season. His average airborne exit velocity is up to 92.7 mph from 89 mph a year ago, suggesting that he now has league average raw power. He has also doubled his rate of Brls/BBE, from 3.9% last year to 7.9% this. Finally, he is pulling many more fly balls (31.3%) than he has historically (21.7% career), making it easier for him to leave the yard. Add in his favorable home stadium and the league-wide power binge, and Gennett's HR/FB likely settles around 17% or so.

Gennett's FB% is virtually unchanged from his career norm (36.4% vs. 33.8% career), but it's high enough to produce reasonable power numbers with an above average HR/FB. Fantasy owners need a reasonable batting average to make reasonable power numbers worthwhile, and Gennett should be able to provide it.

Gennett's .348 BABIP looks unsustainable at first glance, but his career mark of .327 suggests that natural regression won't sting as much as it could. This year's elevated number is the result of fortunate line drives (.824 BABIP vs. .708 career), but his improved contact quality likely explains at least some of the discrepancy. His LD% of 19.9% is also a couple points shy of his career 22.4% rate, so he could mitigate slightly less productive line drives by hitting more of them. Gennett should remain a plus-BABIP guy.

Gennett's plate discipline isn't special, but a 22.5% K% and 10.3% SwStr% aren't that bad in this age of the strikeout. His 32.3% chase rate would also be a career best, giving his 6.3% BB% room to grow as pitchers start respecting his power. Gennett has been hitting fifth of late, providing plenty of RBI opportunities as long as Joey Votto remains a Red.

Gennett won't win your league for you, but his eligibility at 2B, MI, 3B (seven games this year), and outfield (13) makes him an ideal bench piece in formats with daily lineup changes. His versatility is also helpful in deeper leagues, where you do not want to be stuck with an August waiver guy if your star gets injured.

Verdict: Champ

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