Sneaky Fantasy Baseball Waiver Wire Pickups, Buys: Week 6 - Hot Pitchers To Sustain Success?

May 5, 2026

Andy looks at four sneaky fantasy baseball waiver wire pickups for starting pitchers in Week 6 (2026) on hot streaks, and sees if they can sustain their success.

The MLB season is in full swing, and we have now turned the calendar to May. However, even though the first month is behind us, there is still ample time to make up ground in your rotisserie and identify breakout pitchers before the truly "break out" can boost your team significantly.

This week, we will spotlight an emerging arm in the Washington system who had some significant preseason hype but hit a bit of a skid early on, and a recently promoted prospect in Minnesota who appeared to have claimed a full-time role.

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Michael McGreevy, St. Louis Cardinals

20% Rostered (Yahoo)

The St. Louis right-hander has been discussed in this column before, but has continued to enjoy a strong start and is worth a deeper look. In his most recent outing, McGreevy put on a show again at one of the game's most formidable lineups, the Los Angeles Dodgers. Facing the two-time reigning World Series Champions, McGreevy allowed just three hits and three walks over six shutout frames.

He struck out only three batters but lowered his ERA to 2.52 and WHIP to 0.92. On his previous outing, McGreevy looked just as sharp, logging five innings of one-run ball against the Mariners with five hits and no walks. Since the start of the season, McGreevy has allowed more than two runs in two games and allowed one run or fewer in four of his starts.

However, his low 16.3% K% (17th percentile) limits his overall upside in fantasy, which is why McGreevy remains available in nearly 80% of all Yahoo formats. Can McGreevy sustain this success and remain an elite ratio booster?

McGreevy relies on a unique pitch-mix that keeps hitters off balance. Entering Monday, McGreevy has thrown at least five pitches more than 11.0% of the time and has even mixed in a sweeper 8.9% of the time, and a slider, 4.6% of the time. Currently, his four-seamer and changeup are his most-used pitches (25.5% and 21.1% usage rate), but he has begun to deploy his sinker more gradually, particularly over his last two outings.

As shown below, his sinker was thrown more than 17.0% of the time in each of his last two games, and even surpassed the 20.0% usage mark in his most recent outing facing the Dodgers, nearly matching his four-seam and changeup in pure volume.

Relying more on his sinker has been very effective for the 25-year-old. Per Baseball Savant, this has been one of his most effective pitches in the early going, generating a .217 wOBA with a similar .260 xwOBA under the hood, suggesting regression will come, but it will not be overly significant. Under the hood, it limited hard contact, posting a .262 xSLG.

However, his concerns lie with his top two pitches. His four-seamer has posted a strong .282 wOBA on the surface but carries a looming .426 xwOBA, suggesting he could take a massive step back. This pitch has also generated a high .331 xBA (.225 BA) and a .664 xSLG (.400 SLG). His changeup has fared very well on the box score (168 xwOBA), but like his four-seamer has gotten very lucky in terms of expected statistics (.309 xSLG).

Overall, the right-hander carries a 5.78 xERA and a .288 xBA, which place him in the 14th and 13th percentiles, respectively, among qualified pitchers. While his high-end 5.4% walk rate has kept his WHIP low, he is due for significant regression, especially in his ERA.

While McGreevy has been able to avoid this expected regression for nearly a month of work, it is due to catch up, given the large discrepancies in his statistics. He is still worth a look in a favorable matchup, but he is far from the high-end pitcher he looks like on the surface. The rise in his sinker has helped offset this, but his four-seamer and changeup are far from the dominant 1-2 mix they appear to be.

Cade Cavalli, Washington Nationals

18% Rostered

Cade Cavalli made headlines this spring when he logged 14 straight shutout frames with a 10:2 K:BB. This made him a prime late-round post-hype sleeper, as he was slated to enter his first full MLB campaign fully healthy. However, after posting a 4.60 ERA with a 1.72 WHIP and a round 13:12 K:BB over his first 15 2/3 innings, many managers cut ties with the former 22nd overall pick as his control issues made him a weekly landmine.

Despite the slow start, Cavalli has looked far better over his last three games, allowing just two total walks with a 3.00 ERA and 25 punchouts (15 innings), and appears to be turning the corner.

While Cavalli's pitch mix has not changed greatly over the last three outings, he has begun to rely on his knuckle curve significantly more, which has spiked his strikeout totals. In his last two games, Cavalli has recorded 20 punchouts (10 in each game). During these two starts, Cavalli threw his knuckle curve at least 27.0% of the time, which has been among the highest of the young season, as shown below.

This knuckle curve (purple line) has been his primary whiff pitch, and seeing him begin to rely on it as his true No. 2 pitch is an excellent sign of his long-term outlook.

This pitch has generated a .207 xwOBA with an overall 49.0% whiff rate this season. However, the one concern is that his profile has been his four-seamer. So far, this primary pitch has posted a high .458 wOBA, but should see some slight positive regression as shown in the .357 xwOBA under the hood.

Seeing the 27-year-old begin to fine-tune his command has been the catalyst for his recent success. While the track record is not long, managers should be looking to "buy" Cavalli heading into Week 6 as he is showing high-end strikeout totals. His above-average 3.79 xwOBA suggests he should continue to see positive regression, and his WHIP should continue to improve as his command normalizes.

The Oklahoma product has double-digit strikeout upside on a per-start basis, which is often very difficult to find on the waiver wire.

Luis Severino, Athletics

15% Rostered

Luis Severino was a viable starter on the road last season as he held a strong 3.02 ERA with a 1.07 WHIP over 80 1/3 innings. However, when pitching in the hitter's paradise in Sacramento, Severino's ERA rose to 6.01, making him a highly volatile asset in fantasy. Through the early going of 2026, the veteran right-hander has held a 4.46 ERA with a 1.43 WHIP but has been able to find more success, which makes him an interesting name on the waiver wire.

Over his last two starts (one home, one road), Severino has logged 13 2/3 innings with a 1.32 ERA and a 0.95 WHIP. During this stretch, Severino has struck out 13 hitters while walking only three. In his previous 24 2/3 innings (five starts with two at home), Severino has posted a much higher 6.20 ERA, but nine of his 17 earned runs have come in Sacramento.

In these two strong outings, Severino has opted to rely less on his sinker and cutter and instead lean heavily on his sweeper and four-seamer.

This has been an excellent change for Severino as his cutter entering Monday holds a high .439 xwOBA while his sinker sits with a close .436 xwOBA. However, his four-seamer has been far more effective (albeit with a lesser usage rate), posting a .258 xwOBA while his sweeper holds a .249 xwOBA with a solid 23.5% whiff rate.

His four-seam has also been a surprisingly effective whiff pitch (30.90% whiff rate), which is worth monitoring as it is on pace to surpass the 21.9% whiff rate it posted back in 2025. Additionally, Severino has begun mixing in his changeup more often, which has posted a high 35.7% whiff rate with a minuscule .177 xwOBA.

The sample size for this pitch tweak is small, but it has not only boosted his strikeout totals but also given him far more success on the general box score. Overall, the right-hander holds a 4.29 xERA with a strong .223 xBA, both of which suggest he should see better fortunes later this season. His 64th percentile K% should keep him on the high-end streaming radar, especially when on the road.

While he is not a must-roster pitcher, he is entering the high-end SP5 range, especially on extended road trips. This tweak in his pitch-mix could make him a near must-start option when pitching away from Sacramento. The 32-year-old was a viable option in standard leagues when on the road last season, and his recent tweak has put him on track to surpass last summer's K% (17.6%) by a wide margin.

Connor Prielipp, Minnesota Twins

10% Rostered

Rounding out this list will be a pitcher who recently made his MLB debut. Connor Prielipp debuted on April 22 against the Mets, and he tossed four innings of two-run ball with six strikeouts. Over the next two outings, Prielipp would go five innings in each game while allowing four total runs with a 9:5 K:BB.

Overall, the team's No. 5-ranked prospect per MLB.com would hold a 3.86 ERA with a stellar 0.93 WHIP. He would strike out 15 total hitters while showing above-average command with an 8.9% BB%.

Throughout his first three starts in the big leagues, Prielipp has relied primarily on three pitches (at least 14.0% used) and mixed in two pitches (a curveball and a slider, less than 9.0% of the time). His slider leads his arsenal with a 39.7% usage rate and has generated an impressive .218 xwOBA with a 30.4% whiff rate. His primary fastball, a four-seamer, has been thrown 33.5% of the time but has not enjoyed the same success, posting a .492 xwOBA with a low 11.6% whiff rate.

While his changeup has been his clear No. 3 pitch (14.0% usage), it has shown strong promise as a whiff pitch, generating swings and misses at a high 42.9% rate, but has struggled to limit hard contact, posting a .349 xwOBA.

Entering his MLB debut, scouts gave his slider a 70/70 grade in their prospect report, suggesting that not only does this pitch have elite future potential, but it has also already reached that level despite his young age. His changeup also had a 55 future grade, indicating room for further growth, as it currently holds a low 45 grade.

While his sample size is small, in terms of his overall profile, Prielipp has generated a promising 3.46 xERA and an elite .184 xBA, which place him in the 69th and 91st percentiles, respectively. His above-average 35.1% chase rate should keep his strikeout totals high with his slider and changeup doing most of the work.

His command has been an issue at times during his minor league career, but his current 3.21 BB/9 is slightly lower than the 3.38 BB/9 he posted across the Twins system last season. If he can continue to improve his location, Prielipp's slider and changeup could open the door for him to remain an elite strikeout pitcher while maintaining high-end ratios.

The smaller track record and overly modest prospect pedigree do make him a risky pick-up, but he has looked very comfortable in his first taste in the majors. He is worth adding in all 12+ team leagues ahead of the remainder of Week 6.

Connor Prielipp, Wicked 87mph Back Foot Slider. 🤢 pic.twitter.com/lwF4rXppVG

— Rob Friedman (@PitchingNinja) April 27, 2026

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