
Andy looks at five sneaky fantasy baseball waiver wire pickups for starting pitchers in Week 12 (2025) on hot streaks, and sees if they can sustain their success.
As we enter the halfway point of June, we have nearly three months of data to analyze. Through the first half of the season, we have seen several starting pitchers surpass expectations and emerge as viable starting options in all formats.
This week, we will do a deep dive on four starting pitchers who sit under the 25% rostership mark on Yahoo! who have begun to enjoy some previous success. While these starting pitchers may not have the strongest track record, they could be worth a look given their recent production.
Who should fantasy managers be targeting this week? Let's dive in!
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Brandon Walter, Houston Astros
20% Rostered
With the numerous injuries in the Houston rotation, the Astros opted to give Brandon Walter his second look in the big leagues. In 2023, the 28-year-old lefty made his MLB debut with the Red Sox and stumbled as he posted a high 6.26 ERA with a 1.70 WHIP across 23 innings. During this nine-game stint, Walter was deployed out of the bullpen.
He struck out just 16 batters.
During 2024, Walter spent the entire campaign on the Triple-A injured list with a shoulder injury and was eventually signed by the Astros on a minor league deal in late August.
At the start of the 2025 season, Walter was sent to Triple-A Sugar Land, given the time he missed in 2024. However, Walter did not need to wait long as he was given a spot start on May 20 against the Rays. In this outing, the southpaw impressed as he tossed five shutout frames with just three hits and five punchouts. He only walked one batter.
However, after this outing, Walter returned to Triple-A Sugar Land, where he continued to hold his own. Across 47 2/3 total innings of work, the left-hander looked dominant, posting a 2.08 ERA with a 0.76 WHIP. He struck out 49 batters and allowed just seven free passes.
On June 7, Walter was given his second call to the big leagues this season and once again turned in an impressive outing. On June 8, Walter tossed six innings of two-run ball with five punchouts, six hits, and no walks against the Guardians. This strong outing earned him his third start of the campaign. On Sunday, Walter tallied a season-best nine strikeouts across a season-high 6 2/3 innings of one-run ball.
In this start against the Twins, Walter once again did not allow a free pass and surrendered just six hits.
Is this breakout legit?
Unlike previous players in this series, we have very little data to analyze regarding Walter. He has logged just 40 2/3 innings in the big leagues, with 23 of them coming in 2023 as a reliever.
This season, he has deployed his cutter 30.7% of the time (most-used), matching similar usage in 2023 (31.2%). This pitch has generated a .319 wOBA, which is lower than the .335 xwOBA under the hood, suggesting minor regression could be coming. His No. 2 pitch, his sweeper, has been a strong whiff pitch (25.0%) but does not carry positive metrics.
This pitch sits with a .415 xSLG and .253 xBA, much higher than the .353 SLG and .176 BA it holds. However, his changeup (third-most used) is looking quite elite, boasting a 30.8% whiff rate and a stellar .181 xwOBA.
While regression should be expected, his elite command (1.4% walk rate) and improving strikeout production, aided by a changeup, make Walter a strong streaming option in all leagues.
Brandon Walter's 8th and 9th Ks...and Sword ⚔️ pic.twitter.com/CjaUmewX58
— Rob Friedman (@PitchingNinja) June 15, 2025
David Festa, Minnesota Twins
10% Rostered
While Zebby Matthews's emergence at Triple-A this season has overshadowed Festa through the early months, with Matthews now on the IL, Festa should have a clear role in the rotation going forward.
Festa made his big league debut last summer and showed high strikeout upside, tallying 77 in 64 1/3 innings of work, but was tough to trust as he held a 4.90 ERA with a 1.32 WHIP. He returned to the big leagues in April of this season and was impressive, logging 13 innings (three starts) to the tune of a 1.38 ERA and a 1.31 WHIP.
He was then returned to Saint Paul for the next month, but was called back to Minnesota on June 5. Unfortunately, his first start back in the big leagues did not go as planned, as he allowed six hits and eight runs across 3 2/3 innings to the Athletics. However, the Seton Hall product bounced back on Wednesday, June 11, logging six innings of two-run ball (three hits) with a 4:2 K:BB en route to earning his first victory of the season over the Texas Rangers.
While his lone blow-up start has tainted his ratios, removing it, he sits with a rather impressive 1.89 ERA, 1.16 WHIP, and a 19:7 K:BB.
Festa relies primarily on three pitches (four-seamer, changeup, slider) and occasionally mixes in a sinker 8.5% of the time. His four-seamer has not found much success, which is not typically a profile to trust. This pitch has generated a high xBA of .300 and an xSLG of .538, accompanied by a low whiff rate of 9.7%.
However, his changeup (second-most used) has been very effective, generating a .223 xwOBA with an eye-catching 49.1% whiff rate. His No. 3 pitch, his slider, has also been effective in racking up whiffs (37.5%) but holds a .503 xwOBA.
David Festa, Nasty 88mph Back Foot Slider. 😨 pic.twitter.com/fDXBDfWfc8
— Rob Friedman (@PitchingNinja) April 16, 2025
It is worth noting that Festa has deployed his changeup slightly more than his four-seamer in each of his previous two outings. This is something to keep a close eye on as it could help him find better results with his four-seamer, especially if he can mix in his other pitches more often.
While Festa could find value as a streamer in a favorable matchup when looking to add to your strikeout total, his lack of a productive fastball will limit his upside and could derail an outing. He is best left on the waiver wire in standard leagues.
Jacob Lopez, Athletics
2% Rostered
The 27-year-old has bounced between the rotation and the bullpen this season but may be finding his footing as a starter. On Sunday, Lopez turned in his best outing of the season, as he tossed six innings of three-hit ball (no runs) with one walk and nine punchouts. In his previous outing, Lopez was also effective, logging four innings of one-run ball (unearned run) with four hits and five strikeouts.
However, prior to this two-game surge, the lefty posted a high 7.20 ERA, 1.75 WHIP, with a 26:10 K:BB over his first 20 innings of work this season.
Is this two-game stretch legit, or just lightning in a bottle?
Entering this season, Lopez logged just 22 2/3 total innings in the majors across 2023 and 2024 (with the Rays) to the tune of a 4.76 ERA and a 1.24 WHIP.
Lopez has relied primarily on two pitches, his four-seamer and slider (75.1% combined usage), and occasionally mixes in a cutter and changeup. His four-seamer has posted a .256 BA and a .558 SLG, which are much higher than the .199 xBA and .461 xSLG it holds, suggesting regression is on the way. Despite the relatively high base statistics, this pitch has generated a substantial amount of whiffs (29.8%).
His second-most used pitch on the season, his slider, has been dominant, boasting a .240 xwOBA with a similar 28.0% whiff rate. In fact, in his most recent nine-strike outing, his slider was deployed slightly more than his four-seamer.
The 27-year-old sits in the 94th percentile in hard-hit rate and 82nd percentile in xBA.
Lopez is an emerging starting pitcher who is worth a look in all 12+ team leagues. While his track record is not extensive, his metrics suggest he could remain a serviceable SP4/SP5 with high strikeout upside.
Charlie Morton, Baltimore Orioles
15% Rostered
Rounding out this week's column is the man who has much more experience in the majors, Charlie Morton. Morton made my column a few weeks ago after he began his turnaround, and the 41-year-old has continued to shine.
Since May 1, the veteran has posted a solid 3.41 with a 1.25 WHIP. Across these 34 1/3 innings, Morton has struck out 41 batters and allowed just 11 walks. Since June 1, Morton has held a 2.57 ERA with a 1.64 WHIP. During this stretch (14 innings), Morton has struck out 22 batters and allowed only six walks.
This is an incredible turnaround given the 9.45 ERA he held during March and April.
Is this success sustainable?
His primary pitch, his curveball, has continued to improve, which has been the driving force for his success. In April, this pitch held a hefty .397 xwOBA, but he has lowered it to a .281 xwOBA in May and a .226 xwOBA through his first three starts in June. Through June, this pitch has also generated whiffs at a 39.2% rate, a three-point jump in comparison to May.
In addition, Morton has been able to find more success with his four-seamer (second-most used pitch) in June. Through his first three outings this month, this outing has boasted a stellar .166 xwOBA, much lower than the .390 xwOBA it held in May.
Morton has also begun to deploy his changeup more often (8.2% usage in May, 11.4% usage in June), which has also helped him increase his strikeout totals. In May and June, this pitch has boasted a 27.3% and a 28.6% whiff rate. In June, this pitch has also been very effective, generating a .298 xwOBA.
Given Morton's recent stretch of outings and emergence of his curveball, Morton should be viewed as a viable SP4/SP5 option going forward.
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