The Stash Week 13: Top 10 Pitcher Prospects to Stash in 2023

Here are some upside stashes for your redraft leagues.

Welcome to the 13th edition of The Stash List for pitchers! Now that Gavin Williams has made his debut, just about all of the flashiest top pitching prospects have had their chance at the majors this season. Some guys like Ricky Tiedemann and Andrew Painter have been derailed by injuries, but for the most part, we’ve seen a large class of rookie pitchers get a good runway to work with.

Now what we’re left with is a handful of players that are fully blocked by talent ahead of them, have a glaring weakness to continue improving on, or are faster-than-expected risers coming from Double-A. But no matter how you slice it, no one is particularly close to knocking on the big-league door. It’s hard to see any of these guys get called up before the All-Star break barring a big change in circumstances for their MLB team.

So while it’s likely not viable in most leagues to “stash” a lot of these players, I believe this is the group of guys that will be the opportunists of the second half. Think of guys like Hayden Wesneski, Ryne Nelson, and Luis Ortiz last season. You could catch them as streamers in favorable matchups when they get promoted, but most importantly you’ll be the first to properly consider their value for 2024 heading into this offseason. Is it ever too early for future sleepers?


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.


Gavin Williams, CLE (Prev. 1)

Gavin Williams made his MLB debut on Wednesday against the Athletics and it didn’t quite live up to the hype of the whiff rates in Triple-A. In 5.2 IP, he allowed four runs, struck out four batters, and walked three. His velocity across the board was pretty normal but maybe a half-tick below his Triple-A average. He used the fastball a bit less and incorporated his change and curve much more than he had in Triple-A.

I take the usage as a good sign that he’s adjusting to facing better hitters in the majors where it’s much more difficult to live and die by two pitches. However, he only generated seven whiffs on 84 total pitches and also didn’t get very many chases or called strikes. The locations weren’t horrible but he just wasn’t fooling anyone in a poor lineup.

I’ll be the first one to give him another start before I panic because he was able to command a deeper arsenal and stayed around the zone with good quality stuff.


Keaton Winn, SFG (Prev. 5)

Keaton Winn has settled into a role as a long reliever in the Giants’ bullpen. He could easily be a starter, as he’s thrown four and five IP in his two appearances so far. Plus, each of his appearances have come in games where the Giants used an opener instead of a starter. In total, he’s got nine innings with two earned runs, six strikeouts, and three walks. Unless his role and workload become clearer, he’ll continue to be avoided in most formats. But it’s worth noting that his second appearance of five innings was significantly better across the board.


Top 10 Pitcher Prospects to Stash




1. Ben Brown, CLE – ETA July (3)


2023 Stats

Ben Brown takes the top spot on this list for the first time this season thanks to his continued bounce-back from two horrible outings at the beginning of June. He walked 11 batters in 8.1 IP in those two starts, and in his two starts since then he’s only walked two in 10.2 IP. His pitch locations also look much better, as he’s leaving the slider and sweeper down and to the glove side and he’s keeping the fastball up and further away from the middle of the zone too often.

His whiff rates have also been back to his peak levels before the early June hiccups, so right now his biggest obstacle to a promotion is the steady group of MLB starters ahead of him in line.


2. Robert Gasser, MLW – ETA July (6)


2023 Stats

Robert Gasser is another player who is pretty solidly blocked by MLB talent, but he’s only continued his skills improvements that he started about three weeks ago. In his last four starts, he’s got a 2.42 ERA and a 4:27 BB:K ratio in 26 innings pitched. Compare those numbers to the stats in his line above and you can definitely see where he’s taken large strides forward recently.

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.


3. Mike Vasil, NYM – ETA August (4)


2023 Stats

Mike Vasil made his first two Triple-A starts this week and we saw a bit of a mixed bag for the results. His first start was forgettable – he allowed six earned runs, struck out four, and walked two in three innings of work. And then it looked like he turned it around a bit in his second start on Thursday night where he allowed only one run in three and two-thirds innings.

The funny thing is that in his first start he had a significantly better whiff rate, CSW%, and O-Swing%. But overall we’re still looking at a super small sample size of 142 pitches in 6.2 IP. Combined, he’s posted a 12% SwStr%, 26.8% CSW%, and roughly a 28% O-Swing%. Nothing stands out there, but the command has still been pretty good even if it has yet to show in limiting walks.

He’ll likely need to miss more bats to be successful in the majors, and he definitely needs to regain his stellar walk-suppression skills that he flashed in Double-A. But he’s flashed a complementary arsenal that could take a step forward.


4. Will Warren, NYY – ETA July (2)


2023 Stats

Will Warren has been missing from box scores all week, and I can’t seem to find a reason why. I assumed he would start on Friday, one week followed his previous start. But Clayton Beeter was promoted to start instead, and Scranton/Wilkes-Barre has already announced their probable starters for the rest of the weekend series – and Warren’s not on the list. I haven’t found any news about injuries or promotions, so I’m assuming he was skipped for a turn to take a breather in an effort to rekindle some of his Double-A success. Hopefully we’ll have more to look over next week.

Warren features a five-pitch mix. His four-seam fastball is his primary offering and it averages 94 mph. It’s the pitch he’s able to throw in the zone with the most consistency and it generates a fair amount of whiffs and chases, but nothing too crazy. It’s a good table setter.

He has two different sliders- a sweeper in the low 80s that’s his best whiff pitch (but it can have trouble staying in or near the zone), and a mid-to-high 80s power slider that he can throw for strikes much more often. He also has a sinker and changeup but throws them 10% less each and there isn’t a ton of data on them yet. It’s a very interesting profile that’s much more promising than the Triple-A results currently show.


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


2023 Stats

Gordon Graceffo has returned from the IL this week and posted a solid pitching line in five innings across two appearances. He first appeared in a long relief role following a start made by Michael McGreevy, and then the team chose Graceffo to start last night on more normal rest in favor of McGreevy.

Graceffo was the Cardinals’ best pitching prospect by many accounts coming into the season, and he might have been in the mix for a start or two already if not for the bout with shoulder inflammation. The injury should absolutely be considered when weighing his impact for 2023 as shoulder injuries are notoriously a pain to manage.

The good news is that he’s maintained the velocity gains that he made coming into this season, and his individual pitch locations have looked fantastic. He’s gotten really great numbers of whiffs and chases as well. 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 evenly across pitches so far, and his best chase pitch is his slider.


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


2023 Stats

Clayton Beeter earned a promotion to Triple-A for his debut last night after he allowed a total of one earned run across his previous five starts in Double-A. His pitch mix is very similar to Graceffo’s, but his velocity is about one tick lower across the board and he relies even more on his four-seamer and slider. In his debut, those two pitches combined for 86% of his offerings.

Overall, he posted a 13.7% SwStr% and 35% CSW% in his Triple-A debut. Those are solid numbers to backup the stretch of dominance in Double-A, but he’ll have to refine his arsenal a bit more to stay competitive in Triple-A and make a run towards the MLB rotation. I don’t think the fastball and slider are dominant enough to throw that often, so I’m hoping that we see more secondaries his next time out there. There’s good whiff potential here even though there’s a lack of eye-popping velocity.


7. Connor Phillips, CIN – ETA August (7)


2023 Stats

Connor Phillips was dominant again this week in Double-A, and at this point I’m chomping at the bit to get a look at his arsenal in Triple-A without the tacky ball and with Statcast readings. He’s carried a 42.3% strikeout rate and a 2.8% walk rate in his last three starts across 19 innings. Especially after how the team handled Abbott’s promotions, you have to think the 22-year old will get a shot at Triple-A some time around the All-Star break.

Phillips has a really good fastball and curveball and a developing slider and changeup. According to MLB Pipeline, Phillips’ fastball sits between 96 and 97 mph and touches 99. His walk rates have always been above 10%, but he’s definitely improved on them recently.


8. Michael McGreevy, STL – ETA August (NR)


2023 Stats

Michael McGreevy has been pretty solid in Triple-A for the Memphis Redbirds so far, but his most recent start flashed some strikeout potential that has been severely lacking from his profile. He posted a 15.5% SwStr% and a 40% CSW to go along with a 34% O-Swing%. These are all significantly better than what he was posting in his previous handful of starts. The biggest improvement was doubling his SwStr%.

So how did he do it? His velocity was consistent and so was his pitch usage. It looks like he really was able to put his two primary pitches in optimal locations. The sinker bored in on righties to his arm side and the slider swept across the plate to the glove side. In previous starts, they melded in an ugly glob in all areas of the strike zone.

He still has to do this much more consistently to be a threat down the stretch, but he’s definitely more interesting now after his dynamic outing. It looks like he’s lined up to follow it today, so we will get some more data pretty soon.


9. Kyle Harrison, SFG – ETA August (9)


2023 Stats

Kyle Harrison almost had us. He was so close. The rumors were swirling and he was hurling gems. And then it all blew up to the tune of seven runs in two and one-third innings. This outing likely does little to alter the opinions of the Giants organization, as they were likely not seriously considering Harrison for a promotion this last week. He hasn’t really figured his command out yet, even though he has improved.

He’s still got the highest ceiling of anyone currently on this list, and he deserves some grace for being one of the very few legit pitching prospects to pitch in the PCL for the entire 2023 season so far. But he’ll likely continue to take one step forward and two steps back until further notice.


10. Wilmer Flores, DET – ETA August (NR)


2023 Stats

Wilmer Flores has been consistently good since two horrible starts in early April set his ratios back significantly. And in his five most recent starts, he’s also seen some significant gains in his K-BB% (specifically the strikeout rates) to go along with the improved ratios. In those starts, he’s posted a 34% K rate, 12.4% BB rate, and 2.59 ERA.

The Tigers organization doesn’t have a glutton of pitching prospects, and they’re currently dealing with a ton of injuries to their arms across all levels. Flores is likely going to see action in Triple-A pretty soon after the second half begins, if not sooner.

According to MLB Pipeline, Flores primarily features a fastball in the mid-90s (which he’s recently learned to command much better) and his go-to secondaries are a cutter in the mid-80s and a curveball in the high-70s.


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!



He didn’t make the Watchlist yet, but it’s definitely worth noting that Jake Eder made his return from the IL for AA Pensacola last night. He was lighting up AA in 2021 before Tommy John surgery, but we still have yet to see the full effects that the surgery may have had. He looked solid in his three rehab outings at Low-A, but last night he was able to stretch out to 75 pitches and 19 batters faced. His results haven’t been great but he could be a quick riser into the second half and the offseason.


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.

One response to “The Stash Week 13: Top 10 Pitcher Prospects to Stash in 2023”

  1. Will Warren says:

    The Will Warren analysis hit on so many questions I was also trying to figure out. Thank you for voicing your opinions – they are great!

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