
Mike's fantasy baseball waiver wire hitters to add as category boosters for Week 19 of 2025. His top hitters to pick up or stream for HR, RBI, SB, AVG, and runs.
Welcome back to our Fantasy Baseball Waiver Wire Hitters - Category Boosters column for Week 19 of the 2025 MLB season. We are in the thick of it now, and seasons can be won or lost with our waiver wire additions.
With August now ticking away on the calendar, it's time to make up ground on our opponents. We can still gain with savvy moves. This week, I look at some very low-rostered players to try and give you a boost while other players in your league get distracted by fantasy football prep. Stay on your grind, my friends. Let's go win leagues!
We will aim to give you three options for each of the five offensive categories in a standard five-by-five league. Our rule: All hitters will be listed according to their percentage of rostered players on Yahoo!, with a maximum of 50 percent. Let's look at names that might be under the radar, but who can help you now.
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Runs Scored (R) - Fantasy Baseball Waiver Wire Boosters
Blake Perkins, OF, Milwaukee Brewers (3% rostered)
Perkins is not going to be flying under the radar for long, given the injury that sent Jackson Chourio to the IL. Perkins is now the starting center fielder on the best team in baseball. Perkins has scored eight runs since his ascension to the starting nine, and he also had a two-home run game last weekend. Defense and speed are his calling cards; many fantasy players likely have forgotten that he stole 23 bases in a limited role. Grab him now off your waiver wire.
Trent Grisham, OF, New York Yankees (21% rostered)
Similar to Perkins. Grisham has a golden opportunity to play every day with the injury to Aaron Judge. Even upon the slugger's return, Grisham will patrol center field, as Judge will need to DH for the time being. He hit his 20th home run on Sunday, and he has scored six runs over the last week. Grisham will not help your batting average, but the pop and the runs scored can help your team's bottom line.
Lenyn Sosa, 1B/2B/3B, Chicago White Sox (22% rostered)
Sosa is a great example of a useful player who is largely ignored because he plays on a bad team. Sosa had a terrific July, as seen below. He has eligibility at three different positions, which is helpful to your fantasy team. He has career highs already in home runs, runs, and RBI, and still has 50 games to play. Sosa has scored six runs over the last week, as the White Sox, surprisingly, are hitting well since the All-Star break. Consider him this weekend.
Home Runs (HR) - Fantasy Baseball Waiver Wire Boosters
Warming Bernabel, 1B/3B, Colorado Rockies (39% rostered)
Bernabel is going to be a name rostered often this week. Hitting home runs in bunches tends to get you noticed. Since his debut 10 days ago, Bernabel has cranked three home runs and is hitting .417. Of course, the league will adjust, but his power is real. He is hitting fifth or sixth in the lineup while manning first base, but he also has third base eligibility. Get to know him, because it looks like he will get a long runway in this season's second half.
Jordan Beck, OF, Colorado Rockies (31% rostered)
Bernabel's teammate is putting together a nice season. Beck is hitting .279 with 14 home runs, 42 RBI, 12 stolen bases, and 50 runs scored in 2025. Three of those home runs have come in the last week. The move to the cleanup spot suits him well. Beck should continue to play daily and rack up the counting stats. Caveat emptor: the stats do come with a 27.8% K%, so if you are penalized for strikeouts, that is a factor to consider with Beck.
Ryan Mountcastle, 1B, Baltimore Orioles (23% rostered)
If you have read this article at all this year, you know I like to have one pick each week that is almost purely speculative. Mountcastle is my pick this week. He has been on the IL since the end of May with a hamstring issue. Set to be activated later this week, the veteran is destroying the baseball in Triple-A Norfolk, hitting .391 with five extra base hits, including two home runs. With Ryan O'Hearn traded to San Diego last week, playing time should be plentiful for Mountcastle upon his return.
Runs Batted In (RBI) - Fantasy Baseball Waiver Wire Boosters
Andrew Vaughn, 1B, Milwaukee Brewers (47% rostered)
Vaughn was jettisoned from the Chicago White Sox in exchange for Aaron Civale earlier this year. Acquired as a depth piece, injuries to Rhys Hoskins and Jake Bauers opened up a full-time job at first base, and Vaughn has responded in kind. He's hitting 371 over his last 70 at-bats, with six home runs and 24 RBI.
Colson Montgomery, 3B/SS, Chicago White Sox (32% rostered)
Montgomery is hitting for power since the All-Star break with seven home runs on his ledger. Splitting his time between shortstop and third base gives him an added boost to his versatility and ability to help your roster. The Sox did not recall Montgomery from Triple-A to sit; he is going to play. The question is, why isn't he playing for you? Five of his home runs have come in the last 10 days. Roster him for the big swing and power potential.
Ryan O'Hearn, 1B/OF, San Diego Padres (31% rostered)
This is another speculative pick, as he has been cold since he arrived in San Diego. But O'Hearn should get the bulk of the at-bats from the designated hitter spot in a stacked lineup, so the opportunities to drive in runs are there. He may not get the at-bats against tough lefties, and he should also get some at-bats at first base. Check out his Statcast page below; there is a ton of red, and the Padres will need to keep O'Hearn's bat in the lineup.
Stolen Bases (SB) - Fantasy Baseball Waiver Wire Boosters
Luke Keaschall, 1B/2B/OF, Minnesota Twins (25% rostered)
Keaschall was activated from the IL on Tuesday night and immediately reinserted into the lineup, batting fifth and playing second base. We can only hope he picks up where he left off. The rookie homered and knocked in three runs. What caught my eye with him was the five stolen bases in seven games before the injury. There is not a ton of power here, but he should get plenty of at-bats down the stretch for a threadbare Twins team, and hit for average and steal some bases.
Wenceel Perez, OF, Detroit Tigers (3% rostered)
Perez is one of those wildly underrated players who is often forgotten about until you have injuries to star players. You find him and think, "Why haven't I heard of him before?" Well, Perez is now the starting right fielder for the AL Central-leading Detroit Tigers, and he's a sneaky productive player. I know we do not do this, but if you combine his 2024 and 2025 seasons, you get a full season of a .248 batting average, 18 homers, 62 RBI, 14 stolen bases, and 83 runs scored. That's good. Roster him.
Jakob Marsee, OF, Miami Marlins (2% rostered)
Marsee was recalled last week and figures to get the bulk of the playing time in center field as the Marlins examine their top prospects. Marsee's calling card is his speed; he ascended to the major leagues with a whopping 47 stolen bases and 56 runs scored in only 98 Triple-A games. While he does not have any stolen bases yet, expect him to run when he gets on and has the opportunity to do so. It appears he will get a long look over the rest of the season.
Batting Average (AVG) - Fantasy Baseball Waiver Wire Boosters
Spencer Horwitz, 1B/2B, Pittsburgh Pirates (8% rostered)
Raise your hand if you knew that Horwitz has been leading off for the Pittsburgh Pirates over the last few weeks. I did not. Horwitz had a two-home run game last weekend and continues to rake in the early part of August, hitting .389 with four multiple-hit performances in the previous seven games. He's useful, too, because he has both corner and middle infield eligibility. Horwitz is barely rostered and could help your team out in the right situation.
Isaac Collins, OF, Milwaukee Brewers (6% rostered)
If you have not watched Milwaukee play, catch them this week. They are a pleasure to watch, and Collins is a big part of that. The Brewers are 44-16 over their last 60 games, and Collins is a dark horse candidate for Rookie of the Year. See below. He hit .321 in July and is hitting .417 in August, for a .357 average after the All-Star break. All told, Collins is hitting .285 with seven home runs, 37 RBI, 12 stolen bases, and 41 runs scored. He should be on more fantasy rosters. Collins can play.
Daniel Schneemann, 2B/3B/SS/OF, Cleveland Guardians (5% rostered)
Schneemann is a sneaky play because many fantasy players see him only as a role player in Cleveland. He has been batting second and playing mostly outfield with an occasional start at second base. While hitting only .232 for the season, the versatile Schneemann has multiple-hit efforts in four of his last 10 games and is hitting .400 in August thus far. He should continue to get regular playing time with his positional flexibility and production.
I hope this helps you out! Good luck and happy hunting, RotoBallers! You can always message me @mdrc0508 on X to complain about my picks or make other suggestions!
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