Weekly Waiver Wire Roundup — April 27, 2026
Casey Mize posted a 0.71 ERA with a 1.84 FIP and 30.4% strikeout rate across 12.7 innings this week, and at 55% ownership, the window to acquire him is nearly shut — if he's still sitting on your wire, this is the last call. Across 80 rising signals detected over the past seven days, the picture is clear: elite pitching is being scooped up at an accelerating rate, the catcher position is suddenly flush with breakout candidates, and a wave of multi-position infielders is generating the kind of underlying quality metrics that demand attention before ownership catches up.
Top 5 Adds of the Week
Landen Roupp (SP, SF) — 48% Owned (+28% 7d)
Roupp is this week's most urgent add, and the ownership surge reflects it. His strikeout rate climbed to 31.7% over the past seven days, up from an already-strong 27.8% over 30 days, and his 2.65 FIP confirms this isn't just surface-level dominance. Across 11.0 innings pitched in the past week, he posted a 0.82 ERA with a 10.64 K/9. The 28-point ownership jump is the largest among all tracked players this week — he's approaching must-roster territory in all formats, and the five-game sample, while early, is backed by process-level metrics that inspire confidence.
Dalton Rushing (C, LAD) — 27% Owned (+21% 7d)
Rushing's profile this week is a textbook breakout signal at a premium position. His strikeout rate dropped to 22.2% from 25.0% over 30 days while his walk rate surged to 16.7% from 7.5% — that's plate discipline maturation in real time. The batted ball quality backs it up: 54.2% hard-hit rate, 92.1 mph average exit velocity, and a .475 wOBA over five games. Two home runs and a .286 average round out a week where Rushing looked like a different hitter. At 27% ownership, he's still available in the majority of leagues, but that won't last another seven days.
Carmen Mlodzinski (SP/RP, PIT) — 26% Owned (+20% 7d)
Mlodzinski's dual eligibility gives him extra roster flexibility, but it's the pitching metrics that earn him a spot here. A 25.0% strikeout rate, 2.13 FIP, and 10.3 innings pitched across the past week signal legitimate rotation workload and effectiveness. The strikeout rate ticked up from 24.1% over 30 days — a modest but important trend showing he's sustaining his stuff as innings accumulate. At 26% ownership with a 20-point weekly surge, he's being discovered quickly. The FIP is the standout number: 2.13 suggests his results are even better than his raw line shows.
Casey Mize (SP, DET) — 55% Owned (+17% 7d)
Mize was already rostered in over a third of leagues entering the week, and a dominant seven-day stretch pushed him to 55%. The numbers are staggering: 0.71 ERA, 9.92 K/9, 1.84 FIP, and a 30.4% strikeout rate (up from 27.4% over 30 days) across 12.7 innings. That FIP is the second-lowest among all tracked pitchers this week, trailing only Mlodzinski. Mize has always had the stuff — the question was health and consistency. Five games into this stretch, the answer is emphatic. He's the kind of arm that wins you pitching categories in roto and matchups in H2H.
Daniel Schneemann (2B/3B/SS/OF, CLE) — 21% Owned (+10% 7d)
Schneemann is the most intriguing multi-position asset on this list. His wOBA jumped to .508 over the past seven days from .402 over 30 — already a strong baseline — while his walk rate surged to 23.5% from 12.3%. The exit velocity of 94.8 mph and 50.0% hard-hit rate confirm he's not just getting lucky on contact. A .385 average with a home run across five games is eye-catching, but it's the plate discipline improvement and four-position eligibility that make him a priority add at just 21% ownership. In deep leagues, he's a lineup lock; in standard formats, he's an elite utility play.
Biggest Risers in Ownership
Landen Roupp (SP, SF) — +28% to 48%
Already covered above, but the magnitude of this ownership swing deserves emphasis. A 28-point jump in one week means Roupp went from speculative add to consensus roster in every format. The 31.7% K-rate and 2.65 FIP absolutely justify the rush.
Louis Varland (RP, TOR) — +24% to 35%
Varland's 24-point surge is the second-largest this week, signaling that managers across platforms are buying into his relief role with Toronto. While his detailed seven-day stat line isn't among the top adds, the ownership velocity alone puts him on the radar. Monitor his role clarity — if he's locking down high-leverage innings, the rostership is justified.
Dalton Rushing (C, LAD) — +21% to 27%
Rushing's ownership jump aligns perfectly with his production. A .475 wOBA, declining strikeout rate, and improved walk rate make this one of the most data-supported pickups of the week. The scarcity of quality catchers amplifies his value further.
Carmen Mlodzinski (SP/RP, PIT) — +20% to 26%
A 2.13 FIP earns attention from savvy managers, and the 20-point ownership increase suggests the analytical community is ahead of the casual player base on this one. His dual eligibility provides roster construction flexibility that pure starters can't offer.
Casey Mize (SP, DET) — +17% to 55%
Mize crossing the 50% threshold means he's now a must-roster arm in all standard-sized leagues. The 17-point increase on a player who was already well-owned underscores how dominant his week was. Don't let the "already 55%" figure dissuade you — check your wire immediately.
Buy Low Candidates
These are watch-list players whose underlying metrics are screaming, even if their ownership hasn't caught up. The next wave of adds starts here.
Moisés Ballesteros (C, CHC) — 17% Owned
Ballesteros posted arguably the most absurd statline on this entire list: a .621 wOBA, .556 batting average, 70.0% hard-hit rate, and a strikeout rate that cratered from 21.4% over 30 days to just 10.0% this week. The 93.1 mph exit velocity adds a layer of real contact quality. This is an early signal with only five games of data, but at 17% ownership for a catcher with this kind of week, you're getting in at the ground floor. The Cubs' catcher of the future may be announcing himself right now.
Coby Mayo (1B/3B, BAL) — 3% Owned
Mayo's week is the definition of buy-low: a .541 wOBA, 102.6 mph average exit velocity, and 66.7% hard-hit rate — all while his strikeout rate declined from 27.0% to 20.0%. Three home runs and a .333 average across five games at just 3% ownership is a market inefficiency. That exit velocity is the highest among all tracked hitters this week. The raw power is elite, and if the strikeout improvement holds, Mayo is a category-changer at the hot corner.
Nathan Church (OF, STL) — 4% Owned
Church slashed .421 with four home runs and a .581 wOBA across five games while cutting his strikeout rate from 24.3% to 9.5%. The 57.5% hard-hit rate and 94.8 mph exit velocity provide enough batted-ball foundation to believe this isn't entirely noise. Twenty-one plate appearances in seven days confirm consistent playing time. At 4% ownership, he's essentially free — and the power-discipline combination is extraordinarily rare on the wire.
Nathaniel Lowe (1B, CIN) — 1% Owned
Four home runs with a .532 wOBA and an 11.1% strikeout rate (down from 16.7%) at 1% ownership is almost unfathomable. Lowe's 90.8 mph exit velocity isn't elite, and the 50.0% hard-hit rate is merely average, which means this power binge could cool. But the plate discipline metrics — declining K-rate, strong wOBA — suggest a real approach change rather than pure luck. At minimum, he's a streaming first baseman with massive upside.
Mark Vientos (1B/3B, NYM) — 7% Owned
Vientos' ownership is actually cooling off (-4% this week), which creates opportunity. His underlying metrics tell a different story: 80.6% hard-hit rate, 99.2 mph exit velocity, and a strikeout rate that plummeted from 20.0% to 7.7%. A .250 average with one home run doesn't scream breakout, but the contact quality is elite-tier. When a hitter is barreling the ball at nearly 100 mph with an 80%+ hard-hit rate and the ownership is dropping, that's the buy window.
Brady House (3B, WSH) — 5% Owned
House's 88.9% hard-hit rate and 100.4 mph exit velocity are jaw-dropping. His wOBA rose to .339 from .280, and his walk rate climbed to 12.0% from 7.8% — signs of a maturing approach. The .273 average and one home run across 25 plate appearances are modest, but that contact quality profile is among the best on the entire waiver wire. The 5% ownership with a slight cooling trend means you can afford to be patient, but don't wait too long.
Spencer Horwitz (1B, PIT) — 2% Owned
Horwitz posted a .519 wOBA with a .429 average while cutting his strikeout rate to 11.8% from 18.1% and walking at a 17.6% clip. The 94.5 mph exit velocity and 45.8% hard-hit rate aren't spectacular, but the plate discipline is elite. A 2% ownership for a player showing this level of on-base skill is a deep-league steal. He won't deliver power, but he'll contribute in OBP, runs, and AVG formats.
Josh Smith (1B/2B/3B/SS/OF, TEX) — 6% Owned
Smith's five-position eligibility is absurd roster flexibility, and this week he backed it up with a .396 wOBA, 96.8 mph exit velocity, and a strikeout rate that dropped to 10.5% from 18.2%. His walk rate surged to 21.1% from 12.5%. The .357 average without a home run suggests he's generating value through contact quality and discipline rather than power — sustainable skills for a utility asset at 6% ownership.
Jonah Heim (C, ATL) — 0% Owned
A catcher sitting at 0% ownership who posted a 100.0% hard-hit rate and 102.2 mph exit velocity with a .411 wOBA deserves immediate attention. Heim's .364 average across an early five-game sample is backed by elite contact quality. The sample is small and the hard-hit rate will normalize, but at zero cost, there's no reason not to stash him if you need catcher production.
Kyle Karros (3B, COL) — 0% Owned
Karros is essentially invisible on the waiver wire at 0% ownership, yet he posted a .439 wOBA with a 95.5 mph exit velocity, 53.3% hard-hit rate, and a walk rate of 30.0% against just a 10.0% strikeout rate. Playing in Colorado inflates his potential counting stats. The 20 plate appearances confirm consistent playing time. This is a deep-league gem with legitimate everyday upside if the approach holds.
Position Scarcity Report
This week's 80 signals were distributed unevenly across positions, revealing clear trends in where the waiver wire is producing and where it's barren.
Relief Pitching: Loaded
RP led all positions with 11 signals, and SP/RP added six more. The relief pitching market is active, with closers and high-leverage arms generating the most movement. Louis Varland's 24-point ownership surge highlights how quickly elite relievers get claimed. If you need saves or holds, this is the position to attack — but act quickly, as the top arms are moving fast. Names like Lucas Erceg, Trevor Megill, Kenley Jansen, Andrés Muñoz, and Mason Miller all appeared among this week's signals.
Catcher: Breakout City
Ten catcher signals is a remarkable number for a position that's historically the thinnest on the wire. Dalton Rushing, Moisés Ballesteros, Jonah Heim, Patrick Bailey, Mitch Garver, Carlos Narváez, and Ryan Jeffers all generated quality signals this week. If you've been streaming catchers or punting the position, this is the week to invest. Bailey posted a .364 wOBA with a 98.2 mph exit velocity and 61.1% hard-hit rate. Garver cut his strikeout rate from 29.4% to 20.0%. The depth here is unprecedented.
Outfield: Solid but Scattered
Nine outfield signals showed up, with Nathan Church, Brandon Marsh, and Jung Hoo Lee standing out. Marsh posted a 97.1 mph exit velocity with a 75.0% hard-hit rate while dropping his strikeout rate to 12.5%. Lee hit .421 with a .479 wOBA and 10.0% strikeout rate. Dominic Canzone and Carlos Cortes offer less-heralded value at the margins. The outfield wire is healthy this week.
Starting Pitching: Top-Heavy
Only four pure SP signals and six SP/RP signals emerged. The top of the class — Roupp, Mize, Mlodzinski — is exceptional, but the depth drops off quickly. Matthew Boyd and MacKenzie Gore appeared among the signals for managers in deeper formats seeking rotation help.
Infield: Multi-Eligibility Everywhere
The 2B/3B/SS group generated four signals, with Daniel Schneemann leading the charge. The 1B/3B group added three more, and multi-position eligibility dominated the infield landscape. Brett Baty (1B/2B/3B/OF), Josh Smith (1B/2B/3B/SS/OF), and Chase Meidroth (2B/3B/SS) all offer roster construction advantages that amplify their statistical value. Pure shortstop signals were limited to two, making it the thinnest infield position on the wire — J.P. Crawford and Alex Freeland are worth monitoring if you need SS help.
Looking Ahead
The catcher renaissance is the story to track heading into Week 5. With ten signals at the position this week, we're likely seeing a generational wave of young backstops — Rushing, Ballesteros, Narváez — establishing themselves simultaneously, and the ones who sustain their plate discipline improvements will separate from the pack. On the pitching side, watch Landen Roupp's workload closely: 11.0 innings in seven days with a 31.7% K-rate is tantalizing, but early-season arm management could cap his upside in any given week. Finally, keep an eye on the Coors Field contingent — Kyle Karros, TJ Rumfield, Edouard Julien, and Willi Castro all generated signals this week, and the thin air tends to amplify real breakouts while punishing empty ones. Sort the signal from the noise there, and you'll gain a significant edge on your league.