Five hot fantasy baseball waiver wire pickups, streamers, and sleepers for Week 9 (2026). Undervalued hitters outperforming their ownership percentage and should be more widely owned.
Welcome, RotoBallers, to another edition of our Bargain Basement Hitters. With another week of MLB action behind us, it's time to turn our attention to the waiver wire and pick up some hot hitters working.
This week, we have an interesting group of hitters to analyze, as some of them are flashing immense power upside that could carry throughout the remainder of the season.
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Curtis Mead, 1B/2B/3B, Washington Nationals
5% rostered (Yahoo)
Curtis Mead began his career in Tampa Bay and showed some fantasy relevance, but he has rarely enjoyed long-term success. In the 2025 season, he was eventually moved to the White Sox, where he played 41 games.
However, in 2026, Mead found a home in D.C. in one of the game's most dominant offensive units. Through 41 games with the Nationals, Mead has posted a .235/.355/.479 line with a strong .834 OPS. He has already gone deep seven times, which stands as a career-high, and swiped three bags, trailing only two of his best marks in a single season.
He has begun to show even more upside as of late, carrying a .265/.405/.559 line with three of these round-trippers over his last 10 contests. Is this recent power surge the start of a post-hype breakout season?
Based on his Baseball Savant metrics, Mead has the tools to enjoy a breakout campaign. The 25-year-old infielder undoubtedly carries a .370 xwOBA, .264 xBA, and a .468 xSLG, which also place him well above the average marks. He is also impacting the ball very hard, generating a 10.5% barrel rate and a 45.3% hard-hit rate.
Seeing that his xBA is nearly 20 points higher than his surface-level marks suggests his recent surge is quite sustainable.
However, where Mead finds his upside power is his Pull AIR%. Impacting the ball hard helps, but 0ptmizing your swing can take your power production to another level.
Currently, Mead has generated a strong 23.2% Pull AIR%, placing him among the top hitters in the sport. This is also an eight-point jump from his 2025 mark, showing that Mead is showing gradual development with more stable playing time.
In addition to his rise in power, Mead is also showing an elite eye at the plate, which can keep his floor high in points leagues. The 25-year-old has struck out at a low 15.4% rate and holds a 17.4% whiff rate, both of which place him in the 85th percentile or higher. Additionally, his 13.2% walk rate puts him in the 84th percentile among qualified hitters.
Since May 20, Mead has begun to see not only steady at-bats against both left-handers and right-handers, but has been deployed in the two and three holes, putting him in prime scoring positions behind CJ Abrams and James Wood. Batting at the top of one of the game's hottest lineups will keep his counting stats high for the time being.
The strides he has made under the hood look legit, and we could be looking at a true post-hype breakout. His above-average contact and hard-hit rates, paired with a strong eye, will set him up for extended success. Those looking for power upside in the infield should target Mead with confidence this week.
Curtis Mead AGAIN!
The @Nationals SIXTH homer of the game ... this is getting wild 😮 pic.twitter.com/K8kSTFEsEH
— MLB (@MLB) May 25, 2026
Jacob Young, OF, Washington Nationals
5% rostered
After spotlighting one National, let's take a look at another, this time in the outfield. The Nationals have been lighting up the scoreboard over the past few weeks, and a major reason for that has been an unlikely hero in Jacob Young.
Young carried a modest .247/.310/.316 slash line over his first three MLB seasons in 2026 and was more known for his ability to steal bases as he averaged 20.3 SBs per season. However, through the opening months of 2026, Young has begun to tap into some unknown raw power.
Over his first 43 games, Young was holding an expected .213/.269/.307 line with two stolen bases and three long balls. However, over his last 11, the outfielder has looked like a completely different hitter, launching four round-trippers with one stolen base, while holding a .370/.433/.852 line.
Can managers trust this recent home run barrage? Unlike his teammate Mead, whom we discussed above, Young does not boast the same high-end power metrics, which leads to some pessimism about his profile.
Entering Wednesday's slate, Young has generated a low 6.4% barrel rate with a minuscule 35.9% hard-hit rate, both of which are well below the average marks. Despite this, Young has tapped into his raw power through a more refined approach and swing.
The 26-year-old has generated an elite 35.3% squared-up rate with a 38.0% LA Sweet-Spot%, both of which place him among the top of the sport. Additionally, his .269 xBA suggests his early season production was quite unlucky from a batting-average perspective.
However, the most notable component of his profile is his rise in Pull AIR%. We have highlighted this statistic many times in this weekly series, as it is often a strong indicator that a player's recent home run binge is unsustainable. If a player has significantly raised their Pull AIR%, they can tap into more home run potential without needing to impact the ball hard.
So far, Young has generated a 15.5% Pull AIR%, which puts him around the average marks. However, in relation to his previous career rates, this is on pace to lead his career stat line by a wide margin, as he posted a low 5.9% Pull AIR% in 2025 and a slightly higher 7.2% Pull AIR% in 2024.
Like his teammate, Young should also maintain value in deeper points leagues, given his low 17.1% K%. He does not get the same boost, as he only walks 4.8% of the time.
While Mead's production appears to be far more sustainable over the course of the summer, Young is showcasing a far more optimized swing. Those looking for a potent 15-20 HR bat with 20 SB upside should consider picking up Young. The counting stats may not be as consistent as he usually sits at the bottom of the lineup, but he appears to be a viable power/speed threat.
Colton Cowser, OF, Baltimore Orioles
5% rostered
Over the first 36 games of the campaign, Colton Cowser was likely on the waiver wire even in deep AL-only leagues as he carried a rough .169/.270/.195 line with a .464 OPS. During this stretch, Cowser hit just two extra-base hits (two doubles) while striking out at a massive 32.2% rate. However, despite the small sample size, Cowser has begun to turn the corner after his disastrous start.
Over his last nine games, Cowser has launched three home runs (including two walk-off home runs) and gone 7-for-21 with an added stolen base. While he is still striking out at a high 34.1% clip, he is beginning to find his power.
In 92 games last season, Cowser went deep 16 times and swiped an additional 14 bags, which did give him some deep league value despite his low .196 AVG. In the previous campaign, Cowser hit a career-high 24 home runs over 153 games.
While Cowser may not reach this level of play, he could still turn in 15+ HR seasons with the potential for double-digit stolen bases.
Overall, his .207 xBA remains very low, but he is impacting the ball hard, as evidenced by his 11.3% barrel rate. The slugger has also generated a 74.5 mph average bat speed, which is well above the average marks.
Unlike the names above, Cowser's long-term outlook is not as promising. He is generating a weak 14.5% Pull AIR% and a weak .302 xwOBA.
While Cowser should maintain a role in the team's defense, given his 87th-percentile Range and 85th-percentile Run Value, his offensive value will likely be streaky. Managers should only consider picking up Cowser in deeper 15-team, five-outfielder leagues midseason, as his underlying marks and high whiff rates suggest a cold surge could quickly show up in his box scores.
AIN'T THE MILK COLD pic.twitter.com/OnhqTkt92z
— Baltimore Orioles (@Orioles) May 25, 2026
Spencer Horwitz, 1B, Pittsburgh Pirates
5% rostered
While Mead and Young make a strong case, there may not be a hotter hitter in baseball than Spencer Horwitz. Since the start of May, the veteran has posted an impressive .338/.427/.574 slash line with a 1.000 OPS. During this 21-game stretch, Horwitz has tallied five doubles, launched three home runs, and posted a stellar 9:11 K:BB.
Over his first 30 games, he carried a modest .250/.363/.381 line with a .744 OPS and a 15:15 K:BB. While Horwitz figures to be a reliable option in on-base percentage leagues, is this recent surge at the plate sustainable for fantasy?
Unfortunately, compared to the two Nationals we discussed, Horwitz appears to be significantly outperforming his current metrics. When looking at his performance against specific pitch types in May, his wOBA is much higher than his "xwOBA." As shown in the visual below, Horwitz is outperforming his "expected" mark in nearly all three statistics against all three pitch types, which is not the most promising sign.
Overall, Horwitz has generated a solid .333 xwOBA, applying his 60th-percentile mark. He has generally outperformed his .237 xBA and .366 xSLG. He has generated a weak 4.7% barrel rate and 32.8% hard-hit rate.
Given that he does not make the hardest contact, the 28-year-old will need to continue optimizing his swing to sustain this power binge. Currently, Horwitz's 16.4% Pull AIR% does not indicate much confidence in his profile and is likely due to "luck."
However, even if his power production gradually comes back down to earth, he will remain a viable asset in OBP and points leagues. Horwitz has posted an elite 13.3% K% and a 14.4% BB%, both among the best in the sport.
His power upside is not sustainable, but that does not mean he is completely avoidable on the waiver wire. Managers needing a short-term asset in an outfield spot or corner infield should view Horwitz as a top target, but "buy" with caution. Do not overspend your FAAB bid in hopes of chasing statistics that are not sustainable.
Owen Caissie, OF, Miami Marlins
5% rostered
Rounding this list out will be a young outfielder who has been kept in a platoon role in his debut season but has begun to turn the corner. Caissie emerged as a potential early season waiver wire target, but he hit a lengthy skid, which sent him to the waiver wire in most standard leagues.
However, since May 13 (the last 12 games), the former Chicago Cub has begun to heat up at the dish, posting a .300/.364/.567 line with a dominant .930 OPS. During this surge, Caissie has hit two doubles and launched two home runs, but his strikeout rate remains extremely high at 42.4%. Over his first 37 games, Caissie posted a .198/.254/.317 line with a 41.2% K%.
Can fantasy managers trust his recent production? While the 23-year-old holds a modest .204 xBA, he has impacted the ball very hard. The former 45th overall pick has generated a strong 12.2% barrel rate, 44.6% hard-hit rate, and an elite 50.0% LA Sweet-Spot%. Additionally, Caissie's 74.6 mph average bat speed puts him in the 80th percentile among all qualified hitters.
Even though Caissie is consistently generating hard contact, he is still not pulling the ball as much as managers would hope, which has kept his power tally in check.
So far, Caissie has generated a modest 12.2% Pull AIR%, which puts him well below the average marks of hitters. If Caissie can continue to raise this, he could see his power totals soar, given how hard he is already impacting the ball.
While his hefty whiff rates significantly hinder his value in points leagues that punish strikeouts, Caissie could still flirt with a 20-25 HR season if he continues to remain on the strong side of a platoon in Miami. Those falling behind in power categories should continue to keep a close eye on the Notre Dame Catholic SS product.
Owen Caissie long ball.
Big Red goes upper tank and Miami is on the board. It's Caissie's fourth home run of the season.
105.6 mph EV, 403 feet. pic.twitter.com/wLAnl052l6
— Isaac Azout (@IsaacAzout) May 21, 2026
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