MLB Prospect Power Rankings: Top 10 On The Cusp Of Reaching The Majors (May 24, 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) Mitch Keller – Starting Pitcher – Pittsburgh Pirates (5)
After a rough start to the season Keller has seemingly found his footing at Triple-A.  After allowing 1 ER on 6 H and 1 BB, striking out 6, over 7.0 IP in his most recent outing he’s allowed 2 ER or fewer in three of his past four starts.  His WHIP is still rather unsightly (1.45), though in his last 13.0 IP he has allowed just 9 H and 3 BB while striking out 14. 

The key for Keller is the development of a third pitch to go along with his fastball and curveball.  Obviously we can’t tell from just a box score, but it would appear that he’s turned the corner and there’s no question that Pittsburgh has a need in the rotation after Jameson Taillon was placed on the IL (let’s not forget that Steven Brault is still listed as the fourth starter as well).  At this point would it be a surprise if Keller’s next start came in Pittsburgh?

2) Luis Urias – Shortstop – San Diego Padres (2)
After cooling off a bit Urias has turned things back up of late, including a current four-game hitting streak (7-15, 1 HR, 6 RBI, 3 R) and a .351 AVG with 4 HR and 11 RBI over his past 10 games.  It’s getting harder to ignore the power surge while at Triple-A (9 doubles, 3 triples, 12 HR over 123 AB), though expecting him to maintain that pace in San Diego would be misguided (and there also could be a bump in strikeouts, considering a 10.1% SwStr% and 18.9% strikeout rate).

That said he’s clearly figured something out and would be a significant improvement over Ian Kinsler (.184 with 5 HR and 9 RBI) and Greg Garcia.  You have to think that his time is coming soon, don’t you?

3) Yordan Alvarez – Outfielder – Houston Astros (1)
Alvarez is showing no signs of slowing down, hitting .425 with 5 HR over his past five games.  Overall he’s hitting .396 with 19 HR and 57 RBI over 154 AB while showing an ability to make consistent contact (9.6% SwStr% leading to an 18.3% strikeout rate) and draw a significant number of walks (13.9% walk rate).  Obviously a 50.0% HR/FB isn’t maintainable, but there’s no questioning the power potential.  When paired with this approach, it’s a dangerous combination.

Obviously Houston isn’t going to feel pressure to make a move, considering they entered Thursday with the best average (.281) by a healthy margin (second is the Twins at .269), OBP (.355) and SLG (.506).  At the same time they’ve never been a team to rest on their laurels and they continue to get nothing out of Tyler White (.233/.320/.322) and Yuli Gurriel hasn’t been great either (.269 with 2 HR).  There’s an opportunity and he has the potential to make a significant impact.  It’s just a matter of when the Astros decide to pull the trigger.

4) Carter Kieboom – Shortstop – Washington Nationals (9)
As we’ve noted before, Kieboom’s first stint in the Majors didn’t go according to plan but a lot of that was due to poor luck.  Since returning to Triple-A he’s gotten right back to hitting, with a .310/.431/.738 slash with 5 HR and 12 RBI over 12 games.  As the Nationals’ season appears to be spinning out of control, would it really be surprising to see him return to the Majors to fill the void at second base (where his future lies anyways)?  It’s not like Brian Dozier has proven capable of holding down the job and Howie Kendrick hasn’t played the position in the Majors since 2015.  In a lost season why not get Kieboom the experience he needs to hit the ground running in 2020?  He has little left to prove and the Nationals need a spark.

5) Zac Gallen – Starting Pitcher – Miami Marlins (4)
Amazingly the Marlins have still used just five starting pitchers, and while they all have promise four of them continue to carry ERA north of 4.00.  Sooner or later something is going to give, and the team is going to need an additional starter, and Gallen continues to pitch like he deserves the opportunity.  Over his first 9 starts (60.1 IP) he’s posted a 1.79 ERA and 0.65 WHIP, showing all of the skills we look for:

  • Strikeouts – 11.04 K/9 (14.5% SwStr%)
  • Control – 1.49 BB/9
  • Groundballs – 48.4%

Obviously it’s impossible to expect him to maintain this type of production (.184 BABIP, 82.3% strand rate), but it’s also impossible to ignore the skills/upside.  Throw in that he’ll be in a pitcher friendly ballpark and there’s reason to believe that he can make an impact.

6) Dylan Cease – Starting Pitcher – Chicago White Sox (7)
The White Sox rotation is in shambles, and their staff ERA sits at 5.02 (sixth worst in the league and one of seven teams with an ERA above 5.00).  Carlos Rodon has been lost for the season and they are depending on starters like Rodrigo Lopez (5.14 ERA), Ivan Nova (6.96 ERA) and Manny Banuelos (7.26 ERA, and may soon return from the IL).  The team has gone on record as saying they won’t rush Cease, or anyone, to the Majors but you have to think that sooner or later they aren’t going to have a choice.

Cease is doing his best to force the issue, with a 3.71 ERA while showing the ability to miss bats (10.85 K/9 courtesy of a 14.5% SwStr%), avoid walks (2.91 BB/9) and get opposing hitters to consistently drive the ball into the ground (61.4%).  That’s a skillset that will play at any level, and with the team obviously in need once they conclude that he’s gotten enough innings at Triple-A his time is going to come.

7) Kyle Tucker – Outfielder – Houston Astros (NR)
It’s been a tale of two months for Tucker, who was awful in April but has been great in May:

  • April – .173/.221/.407
  • May – .370/.471/.822

He’s also shown a better approach, with 18 K vs. 12 BB.  That said he has an overall 16.1% SwStr%, a step backward from an already concerning 12.2% SwStr% at Triple-A last year.  There is an intriguing blend of power and speed, and that’s going to make him highly intriguing when the opportunity comes.  Where he fits remains a question, especially if Yordan Alvarez has leap-frogged him on the depth chart (though Tucker is on the 40-man roster and could get the first call), and maybe he’s ultimately traded to import rotation help (and expediting his opportunity).

8) Ryan Mountcastle – First Baseman – Houston Astros (NR)
The Orioles are horrific, and while a lot of the issues are in their rotation that’s not to say that there aren’t opportunities in the offense as well.  Mountcastle has shifted to first base this season (35 games at first, 5 at third), and with Chris Davis struggling again it’s just a matter of time before they finally look to replace him.  They could shift Trey Mancini back from the outfield, but why not give Mountcastle a look?

He’s produced in his first taste of Triple-A, hitting .324 with 7 HR and 32 RBI (while adding 12 doubles and 1 triple).  The concern is going to be his lack of walks (3.9%) and potentially to see his strikeouts rise significantly (16.3% SwStr%).  That’s an approach that could be exploited by pitchers at the highest level, though there’s enough here to keep him on your radar.

9) Logan Allen – Starting Pitcher – San Diego Padres (NR)
Cal Quantrill is getting the first opportunity to fill the void at the back of the Padres’ rotation, but it may not be long until Allen gets his turn.  He allowed 11 ER over his first 5.0 IP, but since then has allowed just 7 ER over his next 30.2 innings.  His control has wavered at times (8 BB over his last 12.0 IP), though he posted a 2.83 BB/9 at Double-A last season and still has the upside.  He needs to find that, considering he lacks elite groundball stuff (44.9% in ’19), and while he does have swing and miss stuff (11.6% SwStr%) and pitching in San Diego will help he needs to rediscover his control if he wants to thrive at the next leve.

10) Monte Harrison – Outfielder – Miami Marlins (NR)
Right now the Marlins are using a mix of Harold Ramirez, Garrett Cooper, Austin Dean and Curtis Granderson to fill their three outfield spots.  Do they really expect that group to get the job done?  Maybe Harrison isn’t a significant upgrade, given his propensity to swing and miss (56 K over 152 AB at Triple-A), but there’s never been an argument about his combination of power and speed (6 HR/16 SB this season).  Couple that with the likely opportunity and it’s impossible not to have him on radars.

Also Keep An Eye On:

  • Forrest Whitley – Starting Pitcher – Houston Astros

Graduated to Majors:

  • Cavan Biggio – Second Baseman – Toronto Blue Jays (3)
  • Cal Quantrill – Starting Pitcher – San Diego Padres (6)

Dropped off the Rankings:

  • Nathaniel Lowe – First Baseman – Tampa Bay Rays (8)
  • Keegan Akin – Starting Pitcher – Baltimore Orioles (10)

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

Sources –,, Fangraphs


    • He is back and on the field, so he needs to be on radars, but he’s hitting .171 in the minors and playing at Double-A so it’s going to take some time for him to return to the MAjors


Please enter your comment!
Please enter your name here