Last weekend, right-hander Dustin May debuted for the Dodgers. May, 21, allowed four runs (three earned) across five-plus innings, and struck out only three of the 24 batters he faced. But he showed the easy gas and the high-quality stuff that made him the top pitching prospect in the Dodgers system. Consider how well his fastball and his cutter play off each other in flight:

Good luck, hitters.

May could prove to be an important part of the Dodgers' latest pennant run -- especially if they slide him to the bullpen once the postseason rolls around. Between that possibility and the added significance of internal depth now that there's only one trade deadline, we decided to touch on three other prospects who could impact a playoff race once they're promoted. (Note that for our purposes we considered only prospects who haven't reached the majors.)

Here's our three:

1. Gavin Lux, Dodgers, shortstop

Yes, we're staying with the Dodgers. How could we not? Lux exited the weekend hitting .443/.524/.828 across 29 games in Triple-A. Meanwhile, Corey Seager's second-half OPS is in danger of dipping below .600. Lux has cross-trained on both sides of the bag, so it's at least possible the Dodgers could keep Seager in the lineup while bringing up Lux to man second base. No matter where he plays, he's going to be a good one for a long time.

2. Deivi Garcia, Yankees, right-handed pitcher

We covered Garcia in more detail a couple weeks ago, so pardon our brevity here. But Garcia could make sense as a late-season addition to the New York bullpen. He may end up pitching in relief long-term anyway, so what's the harm of letting him get a taste -- and if his presence there helps the Yankees win some important games? All the better.

3. A.J. Puk, Athletics, left-handed pitcher

Entering the 2018 season, Puk was projected to save the Athletics rotation. He injured his elbow, however, and has since been working his way back. The A's have limited him to pitching relief this year, and it seems likely he'll make his big-league debut out of the bullpen. Puk's fastball-breaking ball combination could make him an impact reliever down the stretch. Oh, and don't sleep on Jesus Luzardo's potential impact for the A's over the coming months, either.

For a look at which prospects to target in fantasy baseball, our Scott White has the latest on Justus Sheffield, Jo Adell, Forrest Whitley and more on his latest edition of prospects report. Now, onto the Watch.

Prospect watch
Diamondbacks
Don't sleep on outfield prospect Corbin Carroll, the No. 16 pick in the 2018 draft. He can really run and hit and there's a chance he remains in center field. Sounds like a good player to us.
Braves
The Braves designated Luiz Gohara for assignment last week. The player they received from the Mariners alongside Gohara, Thomas Burrows, should be reaching the majors over the next 12 or so months thanks to a plus-slider.
Orioles
The Orioles have a fair amount of interesting arms. Zac Lowther is one of them thanks to his solid arsenal and impressive performance in Double-A (2.62 ERA; 106 strikeouts in 110 innings). The fly in the ointment is his walk rate -- he's issued 53 free passes.
Red Sox
Double-A outfielder Marcus Wilson, the return on Blake Swihart, still hasn't tapped into his tools. There's power and speed upside if he can ever figure things out.
Cubs
It's been a while since we've checked in on Dillon Maples. For the season at Triple-A, he's fanned 61, walked 30, and hit six. That's 65 percent of his batters faced. Ridiculous.
White Sox
The No. 4 pick in the 2018 draft, Nick Madrigal recently reached Triple-A. He almost never strikes out, having K'd 16 times in his first 137 professional games.
Reds
Remember Nick Lodolo, the first pitcher taken this past June? He's breezing through the low minors, just as he should. There's at least mid-rotation potential here.
Indians
Scott Moss, acquired as part of the Yasiel Puig-Trevor Bauer trade, is the kind of arm that Cleveland seems to get more from. None of his pitches grade as plus, yet he has length and deception. Cleveland hopes he can tighten up his control.
Rockies
First-base prospects have a tough life. Nobody gets excited unless they can really hit. Grant Lavigne, the No. 42 pick in the 2018 draft, is presently underwhelming in A-ball. He's still a teenager, but therein is the rub: at the cold corner, you're either hitting or you're irrelevant.
Tigers
Isaac Paredes probably merits more love. He has a well-rounded game and could debut next season as a 21-year-old. 
Astros
Now that the Astros have thinned out the top of their system, one name to know is Bryan Abreu. He has nasty curveball and the chance for a couple other above-average offerings.
Royals
Brady Singer has hit his first professional bump in the road in Double-A. There's ample reason to think he'll be just fine.
Angels
The Angels, as an organization, just don't have much pitching to offer. Billy Eppler is going to have to get creative this winter to fix the problem.
Dodgers
Between May and Lux, it's wild to think the Dodgers have one of the top farm systems in baseball to go with one of the best big-league rosters.
Marlins
The Marlins added Jesus Sanchez and Jazz Chisholm at the deadline. Both are high-risk, high-reward prospects. If they hit, Miami could have two future offensive cornerstones. 
Brewers
Nearly four years have passed since the Brewers acquired Trey Supak in what was a small trade. He's finally at Triple-A, and could debut as as back-end starter next season.
Twins
Keep an eye on Chris Vallimont, the prospect Minnesota acquired in the Sergio Romo trade. He has a lively fastball and the Twins could coach more out of him.
Mets
It's probably fair to say, based on allowing nearly an earned run per inning across four starts, that Tony Dibrell is still getting accustomed to Double-A.
Yankees
Southpaw T.J. Sikkema's career is off to a good start: 13 strikeouts, one walk, six hits allowed in his first 10 innings.
Athletics
Parker Dunshee's arsenal is mostly average at best, but he's fanned nearly a batter per inning in Triple-A and could reach the majors next year. He might serve as a back-end starter.
Phillies
Phillies fans who checked Alec Bohm's progress at Double-A following the Maikel Franco demotion were probably disappointed. Still, Bohm is the third baseman of the future -- the future just may not arrive until late 2020 or early 2021.
Pirates
Speaking of third basemen of the future, Ke'Bryan Hayes has scuffled a bit in Triple-A. He'll turn 23 early next year, and still has a chance of locking the position down in Pittsburgh for the long haul.
Padres
Outfielder Buddy Reed has had an uneven season at Double-A. His speed and defensive ability give him a wide berth, but it's unclear if he's more than a reserve outfielder. 
Giants
The Giants received Prelander Berroa in the Sam Dyson trade. He's a teenager walking more than four per nine in rookie ball, but he has a live arm and the chance to pitch in the majors someday.
Mariners
It feels like Joe Rizzo has been in the Mariners system forever. Indeed, the club's second-round pick in 2016 is just now in High-A. He's having a fine season, so that's something.
Cardinals
Given the state of catching, expect to hear more about Ivan Herrera in the years to come. He more than held his own offensively in A-ball, and projects as a solid defender.
Rays
It's probably time to start paying attention to Joe Ryan. Despite the generic name, he's dominated in High-A and could move up soon.
Rangers
Sam Huff continues to run an ugly walk-to-strikeout ratio. But he can hit for power and he grades well behind the plate. That's about all it takes to ensure a lengthy big-league career.
Blue Jays
Miguel Hiraldo is a name to file away for the future. He doesn't have a plus tool, but he's taken well to rookie ball so far.
Nationals
Matt Cronin won't help the Nationals bullpen this season, but based on his pro performance to date -- 20 strikeouts in 10 innings -- it may not be too long before that changes.