How new MiLB rules will affect top prospects

The Minor Leagues will look different in 2021.

OK, most baseball fans likely already knew that, but after Major League Baseball announced Thursday that rule changes were coming to the Minors, it became even clearer that the lower levels were going to take on a new look in the 2021 season.

Let's just do a refresher on what those changes entail exactly. The two Triple-A leagues will both see physically bigger bases come to their diamonds. The bags will expand from 15 inches to 18 inches and will also be made of a material expected to be less slick in rainy weather. Bigger bases mean shorter distances from station to station and could lead to more stolen bases and hits on bang-bang infield plays.

More steals could also come to the High-A and Low-A levels. At High-A, all pitchers will be forced to fully step off the pitching rubber if they want to attempt a pickoff, thus eliminating any delivery trickery or snap throws. At Low-A, pitchers can only attempt two pickoffs per plate appearance without consequence. A third pickoff attempt must be successful or else the hurler is called for a balk.

The Low-A Southeast league will also see an automated balls-and-strikes system commonly known as a robot umpire, and Low-A West will see 15-second pitch clocks, down from the 20-second versions used at Triple-A and Double-A.

Not to be overlooked, Double-A will have a new feature all its own. In an attempt to limit shifts that have become commonplace across baseball, Double-A teams will be required to have four infielders with both of their feet on the infield dirt. No more sticking a second baseman in short right field against a pull-heavy left-handed hitter. There could also be a rule that would force two infielders on each side of second base, but a decision on that won't come until the second half of the 2021 season.

A slew of new rules, all isolated to different levels and even different leagues.

With those in hand, it's time to look at which of MLB Pipeline's Top 100 prospects could be most affected by the changes. A note before we dive in: these are based on where Top-100 prospects are projected to start when the Minor League season opens in May. It's possible prospects could move around in the next six weeks, but as of now, these are how the new rules in each league are expected to influence the stat lines for some of the game's best young talents.

Triple-A (larger bases)

Vidal Brujan, INF, Rays (MLB No. 50)
Three additional inches on either end may not seem like a lot, but for someone with plus-plus speed like Brujan, it could be just enough of a difference to get even more aggressive on the basepaths. That hasn't been an issue in the past for MLB Pipeline's No. 50 overall prospect. He stole at least 45 bags in both the 2018 and 2019 seasons, and his 103 total thefts were tops in all of the Minor Leagues over that span. Under the new rules, it isn't out of the question that Brujan could aim for 60 or even 70 steals in a full season with Triple-A Durham. Of course if he is that accomplished, the 23-year-old would likely be pushing for a job in the Majors well before he could reach his current career high of 55 steals.

Brandon Marsh, OF, Angels (MLB No. 53)
Marsh possesses four plus tools, and one of them is his 60-grade speed. However, the 2016 second-rounder has yet to crack the 20-steal mark in any of his three previous Minor League seasons. Injuries, such as an ankle sprain in June 2019, have played a role in keeping those down, but the bigger bags he'll see in his first trip to Triple-A Salt Lake should provide a boost. Marsh has also been prone to hit the ball on the ground in the past, though he showed improvements in that department each of the last two years. Even if he does hit a few wormburners again this summer, his speed and the slightly closer distance could see him pick up a few more hits than he would have had under the previous rules.

Drew Waters, OF, Braves (MLB No. 35)
No. 12 overall prospect Cristian Pache is the faster Braves outfielder but is more likely to get to Atlanta quickly, if not straight away in 2021. Instead, Waters is a good runner in his own right, earning 60 grades for his speed. Like Marsh, he has been a solid though not quite dominant basestealer thus far in the Minors. His career high for steals was 23, set in 2018 between two Class A levels. Closer bases could allow him to get more aggressive and show off just how well his wheels can play on the dirt. Waters will need to display every part of his skill set, if he is to make the case for a Major League look in the Atlanta outfield alongside Pache and Ronald Acuña Jr. in 2021.

Double-A (positioning restrictions)

Adley Rutschman, C, Orioles (MLB No. 2)
MLB Pipeline's No. 2 overall prospect doesn't need help picking up hits in bunches. Rutschman was a .352 hitter during his college days at Oregon State and earns a 60 grade on his hit tool, a rarity for a catcher such as himself. But upon a likely move to Double-A Bowie, the new rule forcing all four infielders to stay on the dirt could give him an extra advantage. Yes, Rutschman is a switch-hitter, making him all the more difficult to plan for, but he did put up much nicer numbers batting from the left in his brief look at the Minors in 2019, hitting .304/.423/.503 from that side specifically. Any attempt to neutralize him with a second baseman playing back in short right is undone by the new rules, and the potential extra hits could make Rutschman's expected stat line even prettier during his time with the Baysox.

Nolan Gorman, 3B, Cardinals (MLB No. 38)
A left-handed slugger with tremendous power to the pull side and extraordinary exit velocities? Yeah, Gorman is a player you might want to shift against. Unfortunately, Double-A Central defenses won't be able to do that, at least by putting an infielder on the outfield grass. Gorman's biggest offensive issue is his strikeout rate (29.7 percent in 2019), so he may need a few bleeders to get through to prop up his Double-A batting average. No matter the rule change, the biggest show for him will be hitting the ball where the fielders aren't -- well beyond the outfield fence.

Riley Greene, OF, Tigers (MLB No. 21)
Tigers general manager Al Avila said this offseason that Detroit was targeting Double-A Erie for Greene, following his tremendous introduction to pro ball in 2019 and promising showing at last year's alternate site. Though that's subject to change, who could blame the Tigers for pushing the left-handed slugger? What's notable about Greene in this case is that his power is mostly coming to the pull side at this stage of his development. Even with his solid approach, there would have been a big temptation for Double-A Northeast managers to stick their second baseman a few feet back on the grass in the hopes of stealing a few hits from Greene. With that no longer an option and his continued development at the dish, the 20-year-old outfielder's chances at hitting .300 at Double-A just went up.

High-A ("step off" rule)

CJ Abrams, SS, Padres (MLB No. 8)
Abrams isn't ranked as MLB Pipeline's No. 8 overall prospect solely for his 80-grade speed, but it certainly doesn't hurt to possess one of the best run tools in the game. Now, imagine what the 20-year-old shortstop will be capable of on the basepaths when he can't be held so closely by left-handed pitchers, who now must fully step off the mound before attempting a pickoff move. Abrams stole 15 bags in only 34 Minor League games in 2019, following his spot as the sixth overall pick in that year's Draft. He has stayed aggressive this spring and is a perfect 3-for-3 in stolen-base attempts in Cactus League play. A likely move to High-A Fort Wayne would make Abrams even more of a threat to go every time he reaches first.

Corbin Carroll, OF, D-backs (MLB No. 47)
Carroll seems ticketed for Hillsboro in its first season as Arizona's High-A affiliate, and that's an environment the organization's top prospect already knows something about. The 70-grade speedster stole two bases during an 11-game stint with the Hops in 2019, thus finishing with 18 total thefts in 19 attempts over only 42 games played in his Draft year. That put him in a tie for 11th-most in the entire D-backs system that campaign, despite the fact he didn't get started until late June. Carroll was already aggressive in his volume of steal attempts, and that should kick into an extra gear if pitchers can't hold him so closely to first base.

Garrett Mitchell, OF, Brewers (MLB No. 65)
The former UCLA outfielder dropped to the Brewers at the 20th overall spot in last year's Draft in part due to concerns over his Type 1 diabetes. One thing nobody doubts? His 70-grade speed. Mitchell stole 28 bags over 121 games during his three seasons with the Bruins and would have likely added to that total if not for the abbreviated 2020 campaign. Without a Minor League season to ease himself in, Mitchell will get a quick lesson in pro ball with a likely assignment to High-A Wisconsin, but the "step off" rule should ease that transition with more green lights upon reaching first base.

Low-A (pickoff limits, automated strike zone at Low-A Southeast)

Jasson Dominguez, OF, Yankees (MLB No. 32)
New York's top prospect will get plenty of attention wherever he goes in his first taste of the Minor Leagues, and that is widely expected to come at Low-A Tampa starting in May. That attention goes double for opposing pitchers who may be tempted to throw over constantly considering Dominguez's 65-grade speed. The new pickoff limit hurts their chances of doing that successfully. Following a second unsuccessful pickoff, Dominguez (and many Low-A speedsters like him) will be tempted to extend massive leads off first base, leading to easier and more successful stolen-base attempts. A lot of eyes will be on what kind of power Dominguez can deliver stateside, but don't be surprised if his steal total is more eye-popping than his homer number in 2021.

Francisco Alvarez, C, Mets (MLB No. 48)
It's not completely a given that Alvarez will head to Low-A Southeast in 2021, given his experience at last year's alternate site, but it is a firm possibility considering the 19-year-old hasn't seen any full-season level yet. If he does head to Low-A St. Lucie, MLB Pipeline's No. 4 catcher will be met with the so-called "robot umps." That's important to think about because it does take away the receiving aspect of the catching position. A key part of a backstop's development these days concerns his ability to steal strikes with good framing at the edges of the zone. When the human element is eliminated, there are no strikes to steal, meaning Alvarez would have to wait until High-A Brooklyn to measure how well he had developed in that area. Then again if this is the direction the sport is heading, framing could be much less of a necessary skill by the time Alvarez reaches his prime in the Majors. How farm systems work with catchers in Low-A Southeast will require close watching under the new setup.

Mick Abel, RHP, Phillies (MLB No. 76)
Of course, pitchers will likely be even more directly affected by the automated strike zone than their batterymates. Last year's 15th overall pick seems lined up to see Low-A Clearwater at some point this summer, giving him a quick introduction to the robot umpires. Pitchers who worked with the system in the 2019 Arizona Fall League noted that they could particularly get away with called strikes on breaking pitches that knicked the bottom of the zone. How much will be different in 2021 when the system moves from a three-dimensional plane to a two-dimensional one set up at the front of the plate is yet to be seen until it's put in place. But that bottom of the zone might be something Abel and other Low-A Southeast pitchers might want to explore in Florida this summer. The Phillies right-hander already earns marks for hitting his low spots with his mid-90s fastball. Meanwhile, his curve is behind his slider in terms of pitchability right now, but the vertical nature of the deuce might make it a more intriguing option if it crosses the plate at just the right angle and still bounces in front of the catcher.