The Stash Week 17: Top 10 Pitcher Prospects to Stash in 2023

Here are some upside stashes for your redraft leagues.

Welcome to the 17th edition of The Stash List for pitchers!


Ground Rules


  1. The Stash List is for your redraft leagues and does not consider impact beyond 2023
  2. Only current minor league players who are expected to make an impact this season are included
  3. Players who have already made their MLB debuts can not have thrown more than 50 IP in MLB
  4. Upside, proximity, health, and opportunity are all weighed for each player
  5. The focus is on 12-team leagues with standard categories
  6. Rankings and rostership percentages will be updated weekly




This section of the column highlights the pitchers that were on the previous week’s list but have since made their MLB debuts and are no longer considered stashes because they’re still on their team’s active roster. Yet again, we don’t have any to discuss. Second half promotions should start to ramp up around the trade deadline.


Top 10 Pitcher Prospects to Stash



1. Robert Gasser, MLW – ETA July (1)


2023 Stats

Robert Gasser continued his stretch of starts with a vastly improved K-BB% compared to what we’ve seen from him before. He’s still throwing significantly more pitches in the zone, and in this start he only allowed one hard-hit ball. Overall in his last seven starts (not including his start where he faced one batter, hit him, and then was promptly ejected), he’s posted a 29.7% strikeout rate and a 3.4% walk rate, which is good for a 26.3 K-BB% in 43 IP.

Gasser doesn’t have great velocity on any of his pitches, but he’s always carried good strikeout rates in the minors because he has a deep arsenal and varies his pitches well. The biggest issue for him has been his struggles with command. After being promoted to Triple-A last season, his walk rates jumped to about 13% after being below 10% for his minor league career. But now he’s consistently seeing walk rates below 10% again for the first time in a while.


2. Connor Phillips, CIN – ETA August (3)


2023 Stats

Connor Phillips was dominant in his latest Triple-A start last night, and his walk rate was the best that he’s posted at the level so far. After his first Triple-A start, I wrote here about how he had to adjust to the normal ball after using the tacked ball in Double-A, and it looks like he’s now made the adjustment. His individual pitch locations were solid (but there were a few too many high sliders) and he threw a bunch of strikes, especially with the fastball.

Before this start his curveball was his go-to secondary offering, but he swapped and used his slider last night with incredible results. The pitch carried an insane 73% whiff rate (eight whiffs on 11 swings) and 50% chase rate. If he can rely on two plus breaking pitches to work off his 96 mph fastball, he should be successful against MLB hitters when he gets the chance.

There is also more opportunity in the MLB rotation right now than there is for Will Warren, which is another big reason why Phillips was bumped up one spot this week. The Reds’ rotation is dragging behind the offense, and even if they acquire a starter at the deadline, they could still use Phillips’ help down the stretch if he can prove to be reliable.


3. Will Warren, NYY – ETA August (2)


2023 Stats

Will Warren had his start last night cut short because of rain after three innings where he walked two, struck out five, and allowed no runs. While the strikeouts look great, the walks in a short outing are a bit concerning because his pitch locations were all over the map and he threw very few strikes. It’s impossible to know how the rest of the start would have gone, but it could have painted a much worse picture by the time it was over.

He still got a great amount of whiffs overall, and it turns out that a 18% SwStr% can make you easily forgive him for spotty command. The arsenal is one of the deepest in Triple-A and there are so many different ways that he can attack hitters.

Right now it’s hard to see where he fits into the Yankees rotation barring unforeseen circumstances, especially since Nestor Cortes should return from the IL in the coming weeks after starting a rehab assignment this weekend. So at best, Warren is SP7 right now, but Jhony Brito is on the 40-man roster and has been their up-and-down guy so far.


4. Mike Vasil, NYM – ETA August (6)


2023 Stats

Mike Vasil had a very rough start to Triple-A before the All-Star break. His walk rate skyrocketed and he couldn’t make it beyond the third or fourth inning, so in four starts he posted a 8.52 ERA. Now it looks like he’s righted the ship a little bit in his first start out of the break. He went six innings, allowed two runs, two walks, and had five strikeouts.

While the strikeout number doesn’t jump at you, a 16.9% SwStr% definitely will. He commanded his pitches in and around the zone and mixed his secondaries effectively. It’s a really encouraging trend to monitor going forward. We know how much the Mets’ rotation could use some more depth and youth, and they could even be sellers at the deadline. If that’s the case, Vasil would almost certainly get 3-5 starts in the majors to end the season.


5. Gordon Graceffo, STL – ETA August (4)


2023 Stats

Gordon Graceffo has had an absolutely abysmal strikeout rate over his last two starts. It’s a 4:3 strikeout to walk ratio in 12 innings pitched, and somehow he’s managed to only allow three runs in those games. The thing that’s keeping him from tumbling down this list is the good Statcast data that we have from his most recent start on Saturday.

Despite only striking out three of the 24 batters he faced, he posted a 15.2% SwStr%, 28% CSW, and 39% Chase rate. He could have an issue with sequencing or putting batters away, but I’m willing to be optimistic that there’s more in the tank based off those metrics. If you just showed me those approach stats and said he faced 24 hitters, I’d probably guess that he had at least six or seven Ks.

He’s primarily a four-seamer/slider pitcher with slightly above-average velocity and he mixes a curve, changeup, and sinker in as well. He’s spread his whiffs pretty evenly across pitches so far, and his best chase pitch is his slider.


6. Ben Brown, CHC – ETA August (5)


2023 Stats

Following Ben Brown’s season start by start is not for the faint of heart. He’s constantly moving back and forth between getting shelled and looking dominant. And in his last start, he looked dominant, striking out nine and walking one in five innings of scoreless baseball. It seems like he really needs to develop a third pitch because recently he’s relied on his fastball and slider entirely.

My suspicion is that when one of those two aren’t locked in on any given day, he doesn’t have something else to lean on while he figures it out and adjusts. If you have two pitches and can’t throw one of them for strikes consistently, then hitters will sit on your other pitch and crush it.

With that being said, Brown’s fastball and slider are both very good in shape and velocity and his whiff numbers have been consistently great all season. He just desperately needs to develop a plan of attack beyond those two pitches.


7. Mason Black, SFG – ETA August (8)


2023 Stats

Mason Black showed a bit more balanced of a profile in his second Triple-A start. Ironically, he also elected to throw his sinker and slider almost exclusively, as those two pitches combined for 90% of his arsenal. We’ve said it here before that if a pitcher only relies on two pitches, he needs at least one of them to be elite. So I don’t think it’s sustainable for Black to do that against MLB hitters.

However, it worked for him here. He got significantly more chases outside of the zone, with an improved walk rate and a similar strikeout rate. There is another red flag to monitor moving forward, as his sinker velocity was down one tick from 94.6 to 93.6.


8. Clayton Beeter, NYY – ETA August (7)


2023 Stats

Clayton Beeter is another pitcher who benefited greatly from an extended rest period around the All-Star break. His first start back wasn’t super lengthy, but he generated a ton of whiffs and held a really good Norfolk lineup scoreless over 4.1 IP.

The slider is his best pitch and does most of the heavy lifting in getting whiffs. The fastball sits at about 92 mph and while he’s been able to keep it out of the heart of the zone, it’s unclear how it will play against MLB hitters without elite velocity or shape. The good thing is he’s already using that slider a ton – almost as much as the fastball. If he continues to throw his best pitch that often and commands the fastball well, he can be successful at the next level. Especially if he can develop and rely on a third pitch.


9. Nick Frasso, LAD – ETA September (NR)


2023 Stats

Nick Frasso was lights-out for the third start in a row at Double-A Tulsa Friday night. In this start, he set a season-high in innings pitched with five and batters faced with 19. The team has taken great care in protecting his arm since he underwent elbow surgery shortly after he was drafted in 2021.

It wouldn’t be a surprise to see him promoted to Triple-A shortly, even though the Oklahoma City rotation is stacked with veterans and established prospects.

Frasso has a fastball that’s tailor-made for the major leagues. He gets great extension and the pitch sits in the upper 90s with effective armside run, according to mlb.com. We’ll know more about the full arsenal when we get the Statcast data in Triple-A, but I’ll bet on a good fastball any day.



10. Spencer Arrighetti, HOU – ETA September (9)


2023 Stats

Spencer Arrighetti has struggled to maintain a walk rate below 10% since his promotion to Triple-A. his 12.7% mark is currently the highest he’s had at any level, and while an adjustment period to Triple-A is expected, he’ll need to turn it around pretty quickly to be considered for a late-season promotion.

He doesn’t have top-end velocity but his stuff played to get strikeouts in lower levels and his arsenal is anchored by a sweeping slider. His Triple-A whiff rates have been solid, so he might be a eight K/9 pitcher in the majors. He doesn’t have crazy upside but it’s worth it to see if he can make some adjustments and take advantage of the lack of pitching depth that the Astros have right now.


The Watchlist


This section of the Stash List is aimed towards those of you who play in deep leagues (15+ teams or 375+ players rostered) where some of the guys on the list above might already be taken because of their higher pedigree. These players’ debuts will likely be a bit further out than the players listed above, but the purpose is to be ready to pounce on them as soon as it becomes clear that an opportunity might open up.

The players are listed in alphabetical order, and I don’t have the time to do write-ups for these guys, so I’d highly suggest checking out their FanGraphs pages and/or watching one of their starts. Also, shout out to @SpokaneWaUpdate on Twitter for inspiring this section of the article!



Featured image by Justin Paradis (@JustParaDesigns on Twitter)

Jake Maish

Jake is a fantasy baseball writer located in Cincinnati, OH. He plays most fantasy baseball formats but his favorite is H2H categories. When he's not watching and writing about baseball, he's playing board games with his girlfriend, Emma, or playing fetch and/or tug-of-war with their dogs, Moose and Daphne.

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