7 Must-Add Waiver Wire Pickups for Week 19 Fantasy Baseball (2026)

August 1, 2026

Andy breaks down his must-add fantasy baseball waiver wire pickups for Week 19 of the 2026 MLB season. Add these players now off the waiver wire and win more.

Hello RotoBallers! Welcome back to another edition of our 7 Must-Adds ahead of Week 19 of the fantasy baseball season. Prospect promotions will be the highlight in this edition as two high-end names earned the call to the big leagues.

This week, we will spotlight seven players who are available in more than 75% of all Yahoo leagues and explain why managers should prioritize them on the waiver wire. Be sure to follow RotoBaller MLB on X for all of our league-winning content and me @A_Smith_FS.

Additionally, be sure to use discount code SMITH for 50% off any Premium Packages and gain access to our Team Sync platform with customized lineup tools, projections, and more based on your league settings. Let's dive in!

2026 Fantasy Baseball Week 17 Waiver Wire Adds

Max Clark, OF, Detroit Tigers

25% rostered

One of two top prospect call-ups we will spotlight this week is Detroit's Max Clark. Clark is currently viewed as the No. 13-ranked prospect in the entire sport and top option in the Detroit pipeline. Clark has spent the 2026 season at the Triple-A level but has recently begun to flash elite upside at the plate.

Over the first 50 games of the campaign, Clark posted a modest .262/.341/.376 slash line with a .717 OPS, 13 doubles, two home runs and 12 stolen bases. However, since the start of June, Clark has looked like a completely different hitter in the batter's box. During this noted period (40 games of action), the former No. 3 overall pick has carried an elite .294/.402/.506 line with a .908 OPS.

Over this two-month surge, Clark began to showcase his raw power, hitting nine home runs and adding seven doubles and swiping nine bags.

The main question for Clark's fantasy value will be his playing time. Currently, Detroit has an opening in center field with Kerry Carpenter on the shelf, which should give Clark plenty of leeway if he develops growing pains. Additionally, if the Tigers were to part ways with any hitters ahead of the deadline, Clark could also see time in the corner outfield or occasionally at DH.

His five-category upside and high-end prospect pedigree make him worthy add in all five-outfielder leagues.

Max Clark lofts the ball just over the yellow line in right center for his 11th home run of the season. pic.twitter.com/x9lYWimF0D

— Tigers ML Report (@tigersMLreport) July 30, 2026

Heriberto Hernandez, OF, Miami Marlins

17% rostered

Hernandez has quietly been among the game's top power hitters but still sits on nearly 80% of Yahoo waiver wires. Since July 3 (his last 22 games), the young outfielder has slugged eight home runs and carried a strong .280/.337/.659 line with a .996 OPS. During this stretch, Hernandez has held a hefty 33.7% K% but has gotten the job done with power, tallying 14 RBI and scoring 10 runs over his noted stretch.

Prior to this surge, Hernandez posted a lower .218 AVG and sporadic playing time in the Miami outfield. However, his production has not only earned him everyday at-bats but also a path to high fantasy relevance down the stretch.

When looking into the hood, managers can spot many reasons to buy into his recent production. The 26-year-old has generated a .251 xBA, which sits just over 10 points higher than his surface-level .238 AVG.

However, his more impressive metrics come in his raw power. The outfielder has generated an eye-catching .498 xSLG (90th percentile), 13.2% barrel rate (86th percentile), and a 51.1% hard-hit rate (93rd percentile). While all of these metrics sit well above the average, the most notable component of his profile is his optimized swing.

Hernandez has generated a sharp 22.5% Pull AIR%, which has allowed him to raise his home-run ceiling given how hard he already impacts the ball.

With a clear path to at-bats, Hernandez is a must-add ahead of Week 19.

Bot 1st
Phillies 2 | Marlins 2

Heriberto Hernandez solo home run (15)

Exit Velocity: 99.9 MPH
Launch Angle: 35 Degrees#Marlins #FightinFish pic.twitter.com/Kan5glBLPj

— Ricardo Urrusuno (@RickScores) July 27, 2026

Cooper Pratt, SS, Milwaukee Brewers

10% rostered

Pratt has quietly been very productive over his first month of MLB action. Through his first 35 contests with the Brewers, the No. 56-ranked prospect in baseball (per MLB.com) has held a solid .284/.367/.394 slash line with just two home runs. While he's not the most valuable asset for power, he's worth a look for those needing stolen bases.

Pratt has already swiped nine bags in the majors and has shown elite speed while progressing through the Brewers system. Through 58 games at Triple-A prior to his promotion, Pratt swiped 17 bags and added another 31 across 120 games at Double-A in 2025.

While his current power production may not be overly eye-catching, Pratt has begun to make strides at the plate that are worth a closer look. Since July 7 (his last 16 games), Pratt has posted a dominant .377/.417/.585 line with three doubles and both of his home runs.

Under the hood, the infielder has generated a dominant .283 xBA and an above-average .343 xwOBA, suggesting his contact approach should maintain a high average. However, his high-end 40.0% LA Sweet-Spot% and 16.7% Pull AIR% suggest there is a path for more power production.

Speed may be his calling card, but Pratt is also a valuable target for those in deeper points leagues, as he holds a 27.0% Chase% and 17.2% K%, both of which place him well above the average marks of qualified hitters.

Griffin Conine, OF, Miami Marlins

3% rostered

The final hitter we will spotlight this week is a teammate of Hernandez. Even though Conine has been primarily on the strong side of platoon, which has limited his at-bats, he has been very productive when in the lineup and is worth a look in 12+ team leagues.

On the season, the 29-year-old out of Duke carries a .267/.351/.543 slash line with a .894 OPS across 43 games. During this noted stretch, Conine has hit five doubles, one deep nine times, and sneaked into two stolen bases. While his hefty 30.5% K% is concerning like Hernandez, his production in the batter's box is well worth a look on the waiver wire.

Since July 7 (his last 19 games), Conine has quietly been one of the hottest hitters in baseball, posting a .315 AVG with 1.036 OPS and six long balls. While this may seem like a flash in the pan, his underlying metrics suggest this production could be a sign of things to come.

Under the hood, the former 52nd overall pick has generated a high .379 xwOBA, .276 xBA, .522 xSLG, 15.8% barrel rate, and a 56.6% hard-hit rate, all of which would place him among the elite class of hitters. He has also posted a stellar 23.7% Pull AIR%, which has allowed him to hit for home runs as he is pulling the ball at optimal angles.

Don't let the small sample size fool you. Conine can be a high-end contributor for those chasing power and RBI down the stretch.

Griffin Conine crushes a go-ahead two-run homer for the @Marlins 🐠 pic.twitter.com/P6XZGzpoKJ

— MLB (@MLB) July 29, 2026

Quinn Mathews, SP, St. Louis Cardinals

15% rostered

The other big prospect call-up of the week was on the pitching side. The Cardinals will promote southpaw Quinn Mathews to make his MLB debut on Saturday against the Blue Jays. While Mathews was a fast-rising dynasty riser in 2024, he took a massive step back in 2025, which significantly hindered his short-term value.

In 2024, Mathews progressed through the system at a rapid pace, logging 143 1/3 innings to the tune of a 2.76 ERA and a tidy 0.98 WHIP. However, in 2025, he batted injured and was not overly effective, posting a 3.93 ERA with a high 1.60 WHIP through 94 frames at Triple-A.

While his 2026 season began similarly, he has since turned the corner, prompting the call-up. Over the first 35 2/3 innings of the season, the left-hander posted a rough 5.55 ERA and a 1.63 WHIP, which kept him off the starter radar in all redraft leagues.

However, since May 28 (his last 56 1/3 frames), the Stanford product has posted a near-perfect 1.60 ERA and a 0.83 WHIP. He has tallied 67 strikeouts while walking 22 hitters.

His command has been a weakness at times, but given his dominant stretch, he is worth a pickup as a possible high-upside arm for the stretch run.

Brandon Pfaadt, SP, Arizona Diamondbacks

21% rostered

Brandon Pfaadt is the "high-floor" target at the pitcher position this week. Pfaadt struggled early in the season, logging his first 38 innings to the tune of a 5.92 ERA and a hefty 1.50 WHIP. However, after a look in the bullpen, Pfaadt has since been returned to the starting rotation and has looked far more comfortable on the bump.

In his last six starts (since June 30), the right-hander has logged 34 innings to the tune of a 1.85 ERA and a 1.06 WHIP. During this stretch, Pfaadt has shown low strikeout upside, tallying just 18, but has walked only four total hitters, which makes him a great target for those needing a WHIP stabilizer.

His command has been a major strength, as he has walked only 6.8% of the hitters he faced, putting him in the 79th percentile among qualified pitchers. Last summer, he walked only 4.8% of the batters he faced, suggesting there could be room for even further improvement.

While the 27-year-old's strikeout profile is not desirable, he generates groundballs at a high 49.1% rate and keeps hitters off the bases, which makes him a great target for those needing a volume option.

For those in points leagues, Pfaadt has also logged at least six innings in each of his last two games and at least 5 1/3 in all but one of these noted six outings.

Brandyn Garcia, RP, Arizona Diamondbacks

5% rostered

As always, we will round out this column with a target for saves. The major bullpen news of the week came in the desert as the Diamondbacks removed veteran Paul Sewald from the ninth inning. While Sewald has been a high-volume source of saves, he has endured a lengthy skid, which has forced the coaching staff to turn to a different option.

While the bullpen is still quite volatile, the first save opportunity went to Brandyn Garcia, who puts him on our radar. Garcia got the job done on Wednesday, tossing a clean frame with a 2:1 K:BB.

On the season, Garcia has been very productive, which suggests he could quickly claim this role. Through 29 frames, the southpaw has posted a 2.17 ERA with a stellar 0.83 WHIP. He has struck out 31.8% of the hitters he has faced while walking only 6.4%. His high-end 1.81 xERA and .165 xBA suggest his current metrics could be quite sustainable in a higher workload.

He has been a reliable source of holds (13), pitching primarily in the seventh and eighth innings, in front of Sewald. While right-hander Jonathan Loaisiga and Juan Morillo should also see a handful of opportunities, Garcia's dominance this season and performance on Wednesday make him the name to roster in this committee for the time being.

Other Waiver Wire Targets

• Kyle Karros, COL
• Ian Seymour, TB
• Garrett Mitchell, MIL
• JJ Bleday, CIN
• Jacob Webb, CHC
• Francisco Alvarez, NYM
• Kumar Rocker, TEX

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