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Five hot fantasy baseball waiver wire pickups, streamers, and sleepers for Week 6 (2026). Undervalued hitters outperforming their ownership percentage and should be more widely owned.
With another week of MLB action in the books, it's time to do another deep dive into the waiver wire and look at five bargain hitters who are enjoying hot surges who could be worth picking up.
This week, we will look at several former top prospects, including an infielder in Minnesota who may finally be tapping into his perceived fantasy ceiling. As always, the names below are available in over 75% of all Yahoo leagues.
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Brice Matthews, 2B/OF, Houston Astros
5% rostered (Yahoo)
Houston Astros former top prospect Brice Matthews made his MLB debut last summer but was given only a brief taste of the majors. In a 13-game stint, the former 28th overall pick posted a .167/.222/.452 line with a .674 OPS. Even though he appeared in only 13 contests, the young slugger launched four long balls while swiping one base.
He spent most of the 2025 campaign with Triple-A Sugar Land, where he posted a .260/.371/.458 lien with an .829 OPS. Over these 112 games, Matthews went deep 17 times and swiped an impressive 41 bags, showcasing his elite five-category upside. Fortunately, Matthews earned a spot on the Opening Day roster, which pushed him into late-round sleeper theory for those in deep five-outfielder formats.
While playing time was hard to come by early on, the young outfielder has begun not only to carve out a role but also to showcase his true upside in the big leagues. Over his last 13 contests, Matthews has held a strong .279/.347/.488 slash line with three doubles, two home runs, and two stolen bases. For reference, the 24-year-old held a much lower .107/.194/.250 line over his first 14 games.
Is this recent surge legit and a potential sign of a breakout campaign?
The Nebraska product enters Wednesday's slate with an overall .211/.288/.394 line, which does not jump off the page. Under the hood, he has generated a .284 xwOBA with a modest .191 xBA and a .352 xSLG, all of which are well below the average marks. However, he has generated an impressive 38% LA Sweet-Spot%, which places him in the 80th percentile among qualified hitters.
Additionally, despite his lower hard-hit rates, his optimized swing, evident in his high-end 20.5% Pull AIR%, has kept his home run upside high, especially when playing in a park like Daikin Park, which has significantly raised the value of pull-heavy hitters like Isaac Paredes.
Also, while the sample size is small, Matthews has taken steady strides against fastballs, which is key for a young hitter. In 2025, Matthews posted a 50.0% whiff rate against fastballs, but it dropped to 33.3% in 2026. He has also posted a strong .349 xwOBA against this pitch type compared to the .252 xwOBA he posted against it in 2025.
While the former first-round pick will likely remain in a super utility role, seeing time in several outfield positions, the recent season-ending injury to Carlos Correa could open the door for even more at-bats, especially while Jeremy Pena remains on the IL. Matthews is far from a must-add, but he is showing steady progression and could push for a near 20/20 season if he can fully claim a full-time role.
THE BRICE IS RIGHT pic.twitter.com/5sMm6kSsxN
— Houston Astros (@astros) March 31, 2026
Managers in deeper five-outfielder formats should look to add Matthews this week, as he is on the right trajectory and could solidify a permanent spot in the lineup in the coming weeks.
Mark Vientos, 1B/3B, New York Mets
10% rostered
Mark Vientos has been a streaky hitter for most of his MLB career. In 2024, he enjoyed a "breakout" season, launching 27 long balls with a .266/.322/.516 slash line. However, in 2025, Vientos was a major disappointment for fantasy players, posting a much lower .233/.289/.413 line with a modest .702 OPS. During this campaign, the third baseman went deep just 17 times.
Through the early going in 2026, Vientos has begun to rekindle some of his pre-2024 level of play. Through his first 27 contests, the slugger has gone deep four times while holding a .250/.295/.432 line. While he is not a strong target in OBP leagues, his raw power is worth noting. Since April 17, Vientos has been even more productive, posting a .273/.333/.523 line with three round-trippers.
Is this surge just another flash in the pan for the former second-round pick?
While he has been a difficult asset to trust in fantasy, his underlying marks are quite strong and suggest he could be set up well for a bounce-back season. Per Baseball Savant, Vientos has generated an elite .275 xBA with a .502 xSLG, which places him in the 86th percentile. The corner infielder has also hit the ball quite hard, as evidenced by his 44.8% hard-hit rate, and has begun to optimize his swing with a 40.3% LA Sweet-Spot%.
This Sweet-Spot% is a near seven-point jump relative to his 2025 mark.
Looking more closely, we can see that Vientos is due for positive regression across nearly all pitch types. When facing fastballs, he has posted a .321 wOBA, but holds a .368 xwOBA under the hood. When facing offspeed pitches, Vientos has generated a .308 xWOBA with a .271 wOBA on the surface.
While his 13.4% Pull AIR% could be higher, given how hard he impacts the ball, his power numbers should not take much of a hit, even if his swing is not fully optimized for home runs. Another component of his profile that is worth monitoring is his increase in bat speed. Compared to 2025, Vientos has raised his bat speed by nearly 2.0 MPH.
The 26-year-old is not the top target in points leagues given his high 23.2% K% and 30.3% whiff rate, but remains a strong option for those needing a boost in their power totals. With Jorge Polanco and Francisco Lindor still on the shelf, Vientos should continue to see near every day at-bats, and once his positive regression kicks into the box score, the Mets will have a hard time keeping him out of the lineup.
Sam Antonacci, 2B/3B/OF, Chicago White Sox
10% rostered
After looking at a pure power hitter, let's shift gears to a speed threat. The White Sox promoted Antonacci to the MLB roster in April, and after a brief cold spell, the outfielder has begun to find his footing against big-league pitching. Overall, Antonacci has posted a .276/.386/.431 slash line with two doubles, two triples, one home run, and one stolen base over 19 games.
However, Antonacci has carried a .355 AVG over his last 11 contests.
Earlier in the season, Antonacci was sent to Triple-A to make his debut at that level and needed only 16 games before moving to Chicago. In this short stint against the minor league's top pitching, Antonacci posted a .313/.500/.479 line with two doubles, two home runs, and five stolen bases. This uptick in power is worth noting as he only went deep five times over 116 games in the lower levels during the 2025 campaign.
Is this recent surge in power sustainable, or is Antonacci a primary speed option for fantasy?
While Antonacci's top skills will remain his contact and speed, it's worth monitoring his rise in raw power. So far, Antonacci has generated an elite .406 xwOBA with an 11.8% barrel rate and a .494 xSLG during his first taste in the majors. He has posted an above-average 38.5% LA Sweet-Spot% while striking out at a low 10.0% rate.
Even though Antonacci has struggled to pull the ball effectively (9.6% Pull AIR%), his loud contact and whiff rates have kept his ceiling high. Additionally, Antonacci has begun to tap into his raw power. The good thing is that his speed has not been affected, as he currently sits in the 78th percentile in sprint speed.
Managers should not expect the former fifth-round selection to emerge as a 20-HR bat, but a double-digit HR campaign is not out of the question, especially with his playing time. As shown in his minor league track record, his speed is legit, and a 20+ SB campaign is more than plausible. Managers needing a boost in speed with high-end upside in average should prioritize Antonacci on the waiver wire this week.
Brooks Lee, 2B/3B/SS, Minnesota Twins
18% rostered
The next player we will look at is also a former top prospect, like Matthews. Lee joined the Twins with the eighth overall selection in the 2022 MLB Draft and garnered high interest as he progressed through the system. Through 66 career games with Triple-A St. Paul, Lee held a .267/.331/.492 line with an .823 OPS and 13 home runs.
However, this production has yet to translate to the majors, until recently. In 2024 and 2025, Lee posted a .232/.275/.357 line over 189 total games with the Twins. As a result, Lee was an afterthought in all the drafts this spring, but he has made a strong turnaround in his development
In his third campaign in Minnesota, the infielder has posted a much higher .270/.323/.435 line with five home runs and two stolen bases over 33 games. In fact, much of this production has come recently as Lee has held a strong .296/.345/.494 line with four home runs over the last 21 games.
Under the hood, Lee has generated a weak .264 xwOBA, a .212 xBA, and a .322 xSLG, all of which suggest this recent surge is nothing more than a brief flash. However, Lee has made fundamental changes to his swing that have helped him turn the corner, especially in terms of power.
So far, Lee has achieved a 34.1% LA Sweet-Spot% and a 26.2% Squared-Up%, both above average. He has also posted a 40.5% ground-ball rate, which is on track to be his career-best ground-ball rate and raised his Pull AIR% to 20.9%, which has helped raise his ceiling for home runs.
Check this out...
Last 30 days...
Player A: .286 AVG, 5 HR, 16 RBI, 12 R
Player B: .289 AVG, 5 HR, 19 RBI, 15 RPlayer A is CJ Abrams, rostered in 97% of Yahoo leagues
Player B is Brooks Lee, rostered in just 21% of Yahoo leagues.
I am a Brooks Lee truther! Switch-hitter with…
— "Thunder Dan" Palyo (@ThunderDanDFS) May 6, 2026
His strong 21.9% K% should also keep his floor high for those in points leagues, as he does not strike out at a high rate.
While his track record is not long, Lee has begun making the necessary adjustments to achieve greater success against major league pitching. It is also too early to tell if this is sustainable, but for those in deep leagues needing a spark in their infield, they should look at Lee, given his multi-positional eligibility.
Drew Romo, C, Chicago White Sox
5% rostered
The final hitter to discuss this week is Drew Romo of the Chicago White Sox. Romo appeared in just 19 games in the majors over the 2024 and 2025 seasons and was not expected to make much of an impact for the White Sox this season. However, with Kyle Teel on the shelf, Romo has moved into the No. 2 role behind Edgar Quero.
Even though Quero has seen the bulk of at-bats, Romo is making a strong case to push this into a timeshare. Through six games, Romo has hit three home runs while holding a 3:6 K:BB. Through 166 career games at the Triple-A level, Romo has been a high-end power hitter, blasting 25 long balls while holding a .287/.341/.474 line.
Over a short 17-game stint with Triple-A during the 2025 season, Romo posted an elite .946 OPS, which suggests that even though his track record is limited, he does possess high-end raw power that is worth examining.
His underlying metrics in the majors are not worth taking too seriously due to the small sample size. As expected, Romo has generated an incredible 27.3% barrel rate with a 27.3% Pull AIR%, both of which are sure to regress significantly as he earns more playing time. However, he has posted a high 36.4% LA Sweet-Spot% with a 17.4-degree launch angle, which are promising fundamentals.
Managers should continue to monitor the Pull AIR%. If this mark can stay in the high-end tier, his power numbers should remain steady against major league pitching, as they have in the upper levels of the minor leagues.
The lone concern with Romo's outlook is his projected playing time. This current surge could grant him more potential as the DH, but once Teel returns from the IL, his path to everyday at-bats becomes far less clear. For the time being, Romo is best left for deeper 14+ team leagues with two catcher spots.
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