Working The Waiver Wire: May 30th

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  • By Jeff Clowers

    Last Updated on May 30, 2025 6:49 am by Anthony Kates | Published: May 30, 2025

    After back-to-back waiver articles in which I championed some highly-talented players who had still slipped just under the threshold of restorability to be written about, I’m heading back into familiar territory this week, with three of our four players either nearing their MLB debut or having made their MLB debut in the last seven days. That’s right, we’re going prospecting this week!

    But first – call me Frank Gallagher, cause here comes a shameless plug. For all the prospect hounds and dynasty managers out there, be sure to check out my bi-weekly “Dynasty Diamond” article that comes out every second Tuesday. In that article, we focus on the future of baseball, highlighting the most noteworthy statlines from under-the-radar farmhands that are poised to rocket up the rankings – and we do so before the major publications put out their lists, giving you the edge up on your league.

    If the present is your priority though, these three rising stars – and one savvy vet – should provide you plenty of value.

    Marcelo Mayer – SS – BOS – 21% Yahoo, 64% CBS

    Though Roman Anthony is the one that Red Sox fans were clamoring most loudly for to be promoted, they’ll just have to settle for a different top-prospect with budding All-Star abilities. There’s quite the embarrassment of riches up in Beantown!

    At 22-years-old and a shortstop by trade, Mayer doesn’t carry quite the same pedigree as a punishing power-hitter that Anthony does, but he swings the stick well and does so at a more premium defensive position. That’s not to say he’s a slouch when it comes to home run upside either, he just comes in slightly below Anthony with grades (per FanGraphs) of 60 Raw Power and 55 Game Power. Where he falls a noticeable step behind his former Triple-A teammate is his hit-tool. Mayer struggles in particular against off-speed and breaking pitches, focusing mainly on hunting fastballs. That could lead to some lower batting averages as he adjusts to major league pitching but with his swing, he’ll be able to connect with enough fastballs to muscle out a reasonable total of home runs to be fantasy relevant.

    While he has just a single RBI when it comes to counting stats through his first five games, Mayer is at least hitting the ball hard as he sports a 53.3% mark in the category. That’s led to a xBA of .319 in the small sample size we’ve seen but as far as the primary projection systems (Steamer, ZiPS, ATC, etc.) are concerned, Mayer would be expected to hit in the range of .245 with roughly eight home runs should he receive full time at-bats the remainder of the season.

    Of course, there’s no guarantee of that. Mayer was called up in large part due to the “significant” quad strain that Alex Bregman suffered, which is expected to keep him out for at least several months. If he is able to manage to return in late-July, post-All Star break, Mayer could find himself returned to Triple-A if he isn’t showing that he’s quite ready for the big leagues. On the other hand, the Red Sox could also come to the conclusion that Trevor Story, currently sporting a wRC+ that is 41-percent worse than league average, has officially hit rock bottom and should be relegated to the bench, clearing the way for Mayer to revert to his natural position.

    Braxton Ashcraft – SP – PIT – 0% Yahoo, 4% CBS

    Here’s another case where a team called up their “lesser” prospect in lieu of their crown jewel.

    People are now starting to warm to the idea that the Pirates, as moribund as they are in the win-loss column, are somewhat of a pitching factory. Skenes was obviously going to be good anywhere he went but he’s exceeded almost every expectation since being drafted and Bubba Chandler has risen from a potential mid-rotation starter to a potential 1A/1B ace along with Skenes. While he’s not as celebrated as the other two due to being more of a high-floor player than a high-ceiling option, Braxton Ashcraft could eventually prove to be the Cole Hamels to Skenes’ and Chandler’s Roy Halladay and Cliff Lee.

    Grading out as FanGraphs’ 86th-overall prospect on the strength of his plus curveball (55) and plus-plus slider (70), Ashcraft struck out 56 batters in 48.1 innings at Triple-A this year prior to his callup, exhibiting his future strikeout potential. However, although he carried a tidy 0.47 ERA during a four-start cup of coffee at Triple-A in 2024, that figured swelled to 5.03 over 48.1 innings in 2025. That said, it’s fairly easy to point to his career-high 15.6% HR/FB rate as the likely culprit, with his xFIP resting all the way down at 3.88.

    Ashcraft also showed some new-found struggles with walks, having posted a 1.65 BB/9 between 2023-2024 but saw that rise to 3.54 per nine before receiving his promotion. Projection systems think he’ll roughly split the difference between the two figures, ending up somewhere around 2.5 during his rookie rebut to pair with a low-4’s ERA. That’s not the most exciting projection at first glance but they rarely are for rookies unless you’re among the truly elite. Keep in mind what I said about the Pirates’ ability to develop pitching though – there’s a reasonable chance that Ashcraft out-pitches the expectations.

    Considering he’s nearly universally available and held his own in his first career start (3.0IP, 2H, 0R, 1BB, 1K), he’s worth monitoring in leagues as shallow as 12-teams.

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    May 30, 2025, 6:49 am