MLB Prospect Power Rankings: Top 10 On The Cusp Of Reaching The Majors (June 7, 2019)


Which prospects are on the verge of making an impact in the Major Leagues? This weekly column will rank the ten who are closest (as well as other names that are being closely considered). Keep in mind that while talent is factored in opportunity plays a major role, so there may be some “lesser” prospects who rank fairly highly on the list (please note all stats are through Wednesday):

1) Luis Urias – Shortstop – San Diego Padres (1)
The wait continues for Urias’ return, though why remains an unknown.  He just keeps hitting at Triple-A, as he’s 14-35 (.400) with 2 HR and 3 SB over his past 10 games.  Even better he’s struck out (8) just as much as he’s walked (8), and the ratio has been solid over his 169 AB at the level (37 K vs. 27 BB).  The owner of a 9.8% SwStr% there’s reason to believe, and while you may want to question the power surge (27.5%) it’s not the only reason why he’s put his name squarely on our radar.

You can argue that Ian Kinsler has shown some signs of life (.375 with 1 HR over the past seven days), but is that really enough?  He’s still slashing .199/.265/.380 overall this season and is not the future at second base.  It’s only a matter of time until Urias stakes his claim on the job.

2) Mitch Keller – Starting Pitcher – Pittsburgh Pirates (3)
Keller struggled in his first start in the Majors (at least in the first inning), but his first start back at Triple-A was solid as he allowed 2 ER on 3 H and 2 BB over 6.0 IP.  It’s easy to envision him getting a return ticket to the Majors, and fairly soon, and delivering significantly better results this time around.  It’s not like the Pirates don’t have a need at the back of their rotation, with Jameson Taillon sidelined, as Steven Brault (5.45 ERA) and Nick Kingham (8.91 ERA) are currently holding down the final two spots.  Keller is among the best pitching prospects in the league, and with the nerves out of the way the results will be there.

3) Dylan Cease – Starting Pitcher – Chicago White Sox (2)
The White Sox aren’t going to rush anyone to the Majors who they don’t deem to be ready, but for how much longer can they claim Cease isn’t ready?  In 10 starts at Triple-A he owns a 3.46 ERA while showing off all of the skills we look for from a pitcher (10.21 K/9, 3.29 BB/9 and 57.2% groundball rate).  He’s been missing a lot of bats (13.3% SwStr%), which supports him maintaining the strikeout rate, and it’s easy to argue his 1.37 WHIP away due to poor luck (.353 BABIP).  Further supporting a change is how bad some of the starters have been including Reynaldo Lopez (6.62 ERA), Ivan Nova (6.24) and Manny Banuelos (7.36).  Cease has thrown 104.1 IP in the upper levels of the minors, and it shouldn’t be much longer before the White Sox give him a shot.

4) Zac Gallen – Starting Pitcher – Miami Marlins (4)
Gallen just keeps producing, showing no signs of slowing down.  His last start may have been his best of the season, allowing 1 ER on 4 H and 2 BB, striking out 11, over 7.0 IP and he now has a 1.67 ERA and 0.69 WHIP over 81.0 IP.  While he’s shown strikeouts (11.00 K/9 courtesy of a 14.8% SwStr%), control (1.67 BB/9) and enough groundballs (45.3%), all of which would play quite well in Miami, there is the risk of things turning fairly dramatically.  The luck metrics scream of a regression (.200 BABIP, 84.8% strand rate), but that’s obviously not enough to run away.  The skills are there for success and the Marlins are one of the few teams who have only used five starters thus far.  Eventually they are going to need a sixth, and Gallen should be the first man up when the time comes.

5) Ryan Mountcastle – First Baseman – Baltimore Orioles (9)
There have been three young players hyped for the Orioles being promoted at Triple-A, and two of them have arrived (D.J. Stewart and Chance Sisco).  That leaves Mountcastle, and it may not be long until he joins them.  Over his past 10 games he’s hitting .311 with 5 HR and 12 RBI, putting him at .322 with 11 HR and 41 RBI over 205 AB at Triple-A.  When you add in 13 doubles and 1 triple there’s a lot to like in his power, but there are going to be significant questions about his approach.

At Triple-A he’s got 48 K vs. 7 BB, with a massive 15.7% SwStr% causing the issue.  That’s going to help to limit his upside, but that doesn’t mean he should be ignored.

6) Kyle Tucker – Outfielder – Houston Astros (7)
Tucker is back to showing off 20/20 stuff (18 HR/13 SB over 205 AB), and with 51 K over 205 AB his strikeout rate is solid.  He’s also gotten a taste of the Majors before and is currently on the 40-man roster, so it’s easy to argue that he’ll be the first man up (aka before Yordan Alvarez).  At the same time the upside isn’t quite as high and he also hasn’t gotten an opportunity before guys like Derek Fisher and Myles Straw.  Like Alvarez he also could be a better bet if he’s used as a trade chip.

7) Carter Kieboom – Shortstop – Washington Nationals (5)
After returning to Triple-A and streaking initially, Kieboom has slowed down significantly since.  Over his past 10 games he’s hit .184 with 0 HR and 0 SB, lending some credence to his struggles during his first taste of the Majors.  Of course he’s still hitting .307 overall at the level while showing the ability to draw walks (14.8% walk rate), make consistent contact (8.3% SwStr%) and hit for some power (13 doubles, 2 triples and 8 HR).  Even during his time in the Majors he hit the ball extremely hard (43.5% Hard%), showed a solid approach (9.3% SwStr%, 24.2% O-Swing%) and suffered from some terrible luck (.143 BABIP).  With the Nationals’ season quickly disappearing it’s a matter of time before the team takes an eye to the future.  When that time comes Kieboom should be one of the first young players given an opportunity to develop at the highest level, so he’s ready to contribute immediately in 2020.

8) Yordan Alvarez – Outfielder – Houston Astros (6)
Alvarez has finally slowed down, at least a little bit, hitting .243 over his past 10 games.  Of course he’s also walked (11) more than he’s struck out (10) and is hitting .353 with 22 HR and 69 RBI at Triple-A.  From a skills standpoint you could argue that he’s the best player on this list, but he continues to get passed over (Derek Fisher, for example) and isn’t currently on the 40-man roster.  The quickest route to playing time may be via a trade, and we can’t guarantee that it happens.

9) Bobby Bradley – First Baseman – Cleveland Indians (NR)
He’s showing significant power at Triple-A, with 17 HR over 206 AB, to go along with a .286 AVG.  Of course that’s come with significant swing and miss (17.6%), a further regression from his 15.0% mark split between Double and Triple-A a year ago.  Can he make an impact in the Majors with that type of swing and miss, especially since it could further rise with another promotion?  The Indians are falling further and further behind the Twins for the AL Central, and it’s possible they start to take a look at young players with an eye towards the future (they already have given Oscar Mercado an opportunity).  With Carlos Santana at 1B/DH and Jake Bauers a potential fixture in a corner outfield spot, there’s an opportunity for Bradley.  He could be the next Joey Gallo, with a little less power, so keep that in mind.

10) Willi Castro – Shortstop – Detroit Tigers (NR)
The Tigers have used Gordon Beckham (.221 with 3 HR), Ronny Rodriguez (.214 with 6 HR) and Jordy Mercer (.206 with 1 HR) at shortstop this season, which alone tells us that they have a need.  Castro may not be the biggest name, but he’s raking at Triple-A (.335 with 4 HR and 8 SB over 200 AB) and is already on the 40-man roster.  An 11.2% SwStr% from a non-power hitter is going to cause a little bit of a concern, and he also doesn’t offer elite speed (20 SB in ’15 is his career high).  That’s a tough combination to envision making much of an impact, but opportunity and 10/10 stuff should at least put him on your radar.

Also Keep An Eye On:

  • Matt Manning – Starting Pitcher – Detroit Tigers – Casey Mize gets all of the publicity, but Manning has significant upside and could easily be the first to arrive
  • Brendan McKay – Starting Pitcher – Tampa Bay Rays – He’d crack the Top 10 if the Rays didn’t have a history of being conservative with their pitching prospects.  Don’t be surprised if he jumps on to this list before long, however.

Graduated to Majors:

  • None

Dropped off the Rankings:

  • Logan Allen – Starting Pitcher – San Diego Padres (8)
  • Isan Diaz – Second Baseman – Miami Marlins (10)

Currently Injured – Austin Hays (BAL), Jesus Luzardo (OAK), Forrest Whitley (HOU)

Sources –,, Fangraphs


  1. Hey Prof,
    Odd question. I’m receiving offers involving Carrasco (Bell for Carrasco being the latest). How would you value Carrasco now before the details of his health condition are revealed?



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