MLB Prospect Power Rankings: Top 10 On The Cusp Of Reaching The Majors (July 26, 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) Brendan McKay – Starting Pitcher – Tampa Bay Rays (1)
McKay hasn’t pitched at Triple-A after being demoted on July 20, so the last taste we have of him was his first true bump at the Major League level (5 ER over 3.1 IP against the White Sox).  As we noted yesterday it appears likely that the injury to Blake Snell will open up a new opportunity.  Here’s more from that article:

There are going to be questions regarding the number of innings he’s allowed to throw after throwing 78.1 IP last season due to an oblique injury (he’s already thrown 86.0 innings this season).  We also don’t want to draw too many conclusion off of 19.1 IP in the Majors, though he’s shown more than enough control at each level he’s pitched this season (BB/9):

Throw in an ability to miss bats (15.5% SwStr% in the minors, 12.6% in the Majors) and while there are potential home run issues there’s reason to believe he can make an impact.  There should be enough bullets left making McKay an intriguing option (though one you will want to be cautious with when he’s facing teams like the Yankees or Red Sox.

2) Will Smith – Catcher – Los Angeles Dodgers (3)
Keibert Ruiz has been promoted to Triple-A, so you knew that would mean Smith’s time in the Majors could come quickly and with Austin Barnes demoted he’s going to be arriving today.  Smith proved that he could contribute at the Major League level in his first stint (.269 with 3 HR in 9 games) and he’s shown power (20 HR in 223 AB) and a terrific approach (14.6% walk rate, 18.3% strikeout rate, 7.8% SwStr%) at Triple-A.  The Dodgers are cruising in the NL West but it makes sense to get him some experience so he’s ready to contribute in the playoffs.  It’s not like they couldn’t use the help behind the plate, with Austin Barnes (.196/.288/.328) and Russell Martin (.223/.349/.288) helping the Dodgers put up the fifth lowest SLG for their catchers (and also among the ten highest stolen base success rates at 77.1%).

3) Kyle Tucker – Outfielder – Houston Astros (6)
He’s a prime trade candidate as Houston looks to bolster their rotation and prepare for the post season.  That likelihood, which should immediately open up an opportunity, is the only reason that his stock on these rankings continues to rise because if he sticks in Houston it’s hard to envision playing time coming.  It’s fair to have concerns about his ability to consistently make contact, with a 15.3% SwStr% leading to a 24.2% strikeout rate (a mark that could easily rise north of 30% in the Majors).  At the same time there’s no questioning the power and speed he brings, with 25 HR and 21 SB in 343 AB at Triple-A.  Monitor the situation closely, but if he’s dealt don’t hesitate to scoop him up and hopefully get at least a short-term boost.

4) Carter Kieboom – Shortstop – Washington Nationals (8)
The Nationals are surging so maybe they don’t want to rock the boat, but is Brian Dozier really the answer at second base?  He’s hitting just .236 with 2 HR over the past 30 games so sooner or later it will make sense for Washington to get their most talented players in the Majors to help continue their push.  It’s hard to say Kieboom doesn’t deserve another opportunity, especially as he’s currently on an 11-game hitting streak (17-51, 1 HR, 6 RBI, 8 R). Considering he also slashed .322/.451/.544 in June and overall owns a 13.5% walk rate and 8.8% SwStr%, what does he have left to prove?

5) Bo Bichette – Shortstop – Toronto Blue Jays (2)
We continue to wait for Bichette to join Vladimir Guerrero Jr. and Cavan Biggio in the Toronto infield, but for now he remains pinned at Triple-A and he’s struggled over the past week (4-27 with 1 HR and 2 RBI over his past six games).  Still his overall performance at Triple-A has been highly impressive, hitting .288 with 8 HR and 14 SB over 208 AB.  While we’d like to see a few more walks (7.5%), since speed is currently his best asset, a 10.2% SwStr% would play at the highest level.  He’s also not void of power, having added 15 doubles and 2 triples, and that should continue to grow (over the previous two seasons he had 84 doubles, 11 triples and 25 HR).  The Blue Jays kept Guerrero pinned in the minors a year ago and it’s possible that they do the same to Bichette, perhaps because they want him to get more reps at the highest level.  We hope not, but time will tell.

6) Isan Diaz – Second Baseman – Miami Marlins (5)
Could Starlin Castro be moved ahead of the trade deadline?  It’s hard to believe that they’d get much for him, but it’s possible they make the move simply to clear a path for Diaz to arrive.  It certainly makes sense, as Diaz continues to roll at Triple-A and is currently on an 11-game hitting streak (19-48, 4 HR, 10 RBI, 10 R, 1 SB).  There is a bit of swing and miss to his game (11.0% SwStr% at Triple-A) and a question as to whether or not he could get too home run happy (he has 24 HR this season, though just 20 doubles and 2 triples).  That said it appears that his approach is solid (11.3% walk rate) and his strikeout rate isn’t abysmal (22.1%), though it could regress against more advanced pitching.  Obviously there’s always a risk of a stumble, and it’s possible his power takes a step back playing half his games in Miami, but it would appear that his time is coming quickly.

7) Mitch Keller – Starting Pitcher – Pittsburgh Pirates (7)
After a terrible start on July 4 Keller has rebounded well, posting three straight solid starts (17.0 IP, 3 ER, 10 H, 5 BB, 18 K).  While he hasn’t lived up to the hype in his three starts in the Majors, we all know he’s better than his 10.50 ERA and he also has little left to prove at Triple-A.  While we’d love to see him generating a few more groundballs a 44.1% mark is hardly crippling, especially when paired with strikeouts (10.26 K/9 courtesy of an 11.9% SwStr%) and control (3.19 BB/9).  The Pirates pitching staff owns a 4.95 ERA and they may not get Jameson Taillon back this season.  It just makes sense to give Keller another opportunity.

8) Jake Fraley – Outfielder – Seattle Mariners (NR)
Fraley is back after missing just under a week, and that’s going to lead to speculation for the rebuilding Mariners once again.  As we’ve said it shouldn’t be hard for the team to find AB for the breakout outfielder, especially with the potential for various players to be moved ahead of the deadline, who is hitting .298 with 16 HR and 20 SB over 325 AB split between Double and Triple-A.  With speed being hard to find his potential impact makes him potentially more valuable in the short-term.  Health has been one of the biggest concerns hanging over him so any missed time is going to raise a red flag, but this appears to be behind him so he can start pushing for a promotion once again.

9) Jon Duplantier – Starting Pitcher – Arizona Diamondbacks (NR)
He’s off the IL but instead of rejoining the Arizona rotation immediately he’ll spend some more time at Triple-A.  It was only 25.0 innings in the Majors but there definitely is some intrigue.  He’s continually shown an ability to generate groundballs as he’s evidenced through the minors (1.55 career GO/AO) and he’s paired it with strikeouts and enough control.  Considering the questions in the Arizona rotation, just how long will it be until he’s brought back to the Majors?  It shouldn’t be long, and while he may not be more than a streaming option there’s enough there to pique our interest.

10) Ryan Mountcastle – First Baseman – Baltimore Orioles (NR)
It shouldn’t be hard for him to find at bats with the Orioles once he’s deemed ready and there’s no question that he has the potential to add some thump to the lineup (19 HR in 385 AB at Triple-A).  The question is whether or not he’s going to make enough contact to tap into it, as he has 97 K vs. 14 BB.  That’s something more advanced pitching is going to take advantage of and it could lead to some ugly numbers.  The Orioles may let him learn on the fly and he could provide a short-term boost, so at least have him on your radar.

Also Keep An Eye On:

  • Jo Adell – Outfielder – Los Angeles Angels – He’s playing at Double-A so it’s hard to call his arrival imminent, but the Angels could be aggressive if they are in position for a playoff spot
  • Gavin Lux – Shortstop – Los Angeles Dodgers – He’s doing his best to force the issue, but with Corey Seager back there is no obvious opening for Lux to break through at the highest level.
  • 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
  • Luis Robert Outfielder – Chicago White Sox – He’s been promoted to Triple-A, but that doesn’t mean that he’s on the precipice of arriving.  The White Sox have a slew of outfielders already on the 40-man roster who can step in, including Luis Alexander Basabe, Adam Engel and Daniel Palka, and at 21-years old it makes sense to not force the issue.

Graduated to Majors:

  • Luis Urias – Shortstop – San Diego Padres (4)

Dropped off the Rankings:

  • Tony Gonsolin – Starting Pitcher – Los Angeles Dodgers (9)
  • Enyel De Los Santos – Starting Pitcher – Philadelphia Phillies (10)

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

Sources –,, Fangraphs


  1. Hello Professor,

    This is slightly off topic, however drop Canning, Beede or Stripling to activate Wheeler today?

    Next week Stripling @Col, Beede@Phi and Col but I would sit him @Col, Canning vs Det.

    Thanks again for your thoughts

    • Stripling is completely unusable and I believe he’s battling a little bit of an injury. Depending on the format he’d be my first drop

    • You could make the argument that JAnsen is better right now. Smith has a much higher upside than the other two though and he could make a signifiant impact down the stretch


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