Ranking the Top 10 MLB Rookie of the Year Candidates Entering 2021 Season

Developing young talent is as important as it has ever been in baseball. Rookies could have an enormous impact on their respective franchises in 2021.

Rebuilding clubs like the Detroit Tigers have young arms like Casey Mize and Tarik Skubal, both of whom are pivotal to the team's future. Meanwhile, the likes of Randy Arozarena and Ian Anderson will be crucial pieces to their team's hopes of contending. Then there are the prospects who could eventually make their mark, including Wander Franco and Jarred Kelenic.

There are a number of rookie storylines to follow this summer. It should make the Rookie of the Year race all the more interesting.

The following is a ranking of the rookies most likely to capture ROY honors. It's based on their past production, upside and expected role in 2021. That means players likely to start on Opening Day take precedence over the others since they will have a head start in putting up numbers. 

The rankings are also devoid of league considerations, meaning they include both National League and American League players. We should also note MLB amended rookie status last fall, meaning the likes of Jo Adell, Andres Gimenez and James Karinchak no longer possess rookie eligibility.

Let's get started with some honorable mentions.

The following players just missed the cut:

• Wander Franco, Tampa Bay Rays
• Bobby Witt Jr., Kansas City Royals
• Triston McKenzie, Cleveland
• Cristian Pache, Atlanta Braves
• Alex Kirilloff, Minnesota Twins
• MacKenzie Gore, San Diego Padres
• Nate Pearson, Toronto Blue Jays
• Dane Dunning, Texas Rangers
• Tarik Skubal, Detroit Tigers

I tend to believe Seattle Mariners outfielder Jarred Kelenic will arrive first in the trio of top prospects that includes Wander Franco and Bobby Witt Jr.

Franco is MLB.com's No. 1 prospect. But the Tampa Bay Rays reassigned him last week, and Rays manager Kevin Cash expressed confidence in his position players. A Willy Adames trade could pave the way for Franco, but his timeline is hard to project.  

Witt was the talk of Royals camp this spring. But Ken Rosenthal and Alec Lewis of The Athletic reported Sunday he had been demoted. Considering Witt has only played 37 games of rookie ball, he could see a greater chunk of time in the minors. 

Alas, we arrive at Kelenic. Mariners general manager Jerry Dipoto said last week (h/t Daniel Kramer of MLB.com) Kelenic is likely to break camp in the minors, possibly resulting in Taylor Trammell starting in left field.

But left field could be a revolving door, and Kelenic has been tremendously impressive this spring. The 2018 first-round pick missed some time this spring with a left adductor strain, only to return with a pair of hits on Friday and a homer on Sunday. He has a 1.212 OPS in seven games. 

Kelenic had already made a statement at summer camp last season. His talent has been every bit as tantalizing over the course of the past months. He should get his opportunity sooner rather than later.

Chicago White Sox youngster Andrew Vaughn is another prospect who has barely gotten his feet wet in professional ball. Yet, there is no question as to where he will be to start the season.

White Sox management has raved about Vaughn's work ethic and hitting ability. The team has even broached the subject of a contract extension, per ESPN's Jeff Passan. He is all but guaranteed to be Chicago's designated hitter on Opening Day.

Vaughn was selected just one pick after Witt in 2019 at No. 3 after starring at California. He made it all the way to High-A ball in his first pro season and is now ready to make a splash in the majors.

The 22-year-old projects as a pure hitter with ample slugging potential. Vaughn earned a 65 hit grade and 60 power grade from MLB.com. He has shown some of that potential in spring training, slashing .293/.408/.512 with a pair of homers in his first 18 games. 

Vaughn can be a major run-producer in a dangerous White Sox lineup. He can also spot Jose Abreu the occasional day at first base, though he is likely to spend the majority of the season in the DH spot.

Make it back-to-back appearances for the White Sox on this list.

Nick Madrigal made his highly anticipated MLB debut in 2020, though it produced mixed results. Madrigal flashed his tremendous hit tool, compiling a .340 batting average in 109 plate appearances. Unfortunately, his debut was cut short by a separated left shoulder. 

However, the former Oregon State star is looking healthy.

Madrigal, who underwent surgery in October, is already doing what he does best. Madrigal had four hits in his first 11 plate appearances this spring and looks ready to be the team's starting second baseman on Opening Day.

Aside from the pure hitting ability, Madrigal can really run and play a terrific second base. In his 29 games last year, he ranked in the 77th percentile in sprint speed and 85th percentile in outs above average. 

Madrigal could score a lot of runs in Chicago while stealing some bases and playing plus defense. The only reason he isn't higher in these rankings is he does not project as much of a slugging run-producer.

Having said that, Madrigal's contact-heavy approach is a nice complement to slugging-oriented bats of Eloy Jimenez and Luis Robert. It makes the White Sox's lineup all the more balanced.

Bobby Dalbec impressed in his brief big-league showing last season, and he has been all the more prolific this spring.

Dalbec is slashing .324/.395/.824 with five homers and 12 RBI through his first 14 games in camp. He has shown power to all fields. The right-hander's stance and batting stroke through the zone also look eerily similar to that of Mike Trout. 

The 25-year-old's strong performance in camp is all the more encouraging considering what he did in 2020. Dalbec hit eight homers with 16 RBI, a .959 OPS and 152 OPS+ in 23 games. That stint basically made Boston's first base job his to lose this spring. Suffice to say, Dalbec has gone out and earned the job.

There will be questions about Boston's rotation as the Red Sox look to be more competitive in the AL East. But this is a lineup that ranked fifth in the AL in runs scored and third in OPS in 2020 despite down years from J.D. Martinez and Rafael Devers.

Boston's explosive offensive potential means Dalbec could put up big numbers as the team's starting first baseman. That bodes well for his ROY chances.

St. Louis Cardinals outfielder Dylan Carlson really struggled to live up to his billing as the team's top prospect in 2020. But those struggles need added context. 

Carlson hit just .176 with a .498 OPS in his first 21 games. But he found his power stroke at the end of the season. 

The 22-year-old had seven extra-base hits—including two homers—and 11 RBI in his final 14 games in September. He kept the ball rolling in the Wild Card Series, even showing better plate discipline with four walks in three games.

Now, Carlson will play a big role in the team's outfield picture in 2021.

Carlson clearly has slugging upside. His hard-hit rate (42.1 percent) also suggests he should have better luck on batting average on balls in play going forward.

The other tools are there as well. Carlson ranked in the 75th percentile in sprint speed. He played all three outfield spots in 2020, finishing the season with 4.0 defensive runs saved and a 3.6 ultimate zone rating.

One of the other reasons Carlson ranks highly? He basically has to perform well to keep his job. Lane Thomas is waiting in the wings. 

Carlson has shown some positive signs this spring (.780 OPS in his first 12 games), and he should increase his comfort level and production. He will be an important part of St. Louis' hopes in the NL Central.

Baltimore Orioles fans might not have a ton to be optimistic about from a team success standpoint. But their youngsters are starting to arrive in the bigs, and Ryan Mountcastle is a headliner. 

The 24-year-old attracted some national attention in 2020, slashing .333/.386/.492 with five homers and a 140 OPS+. He finished eighth in the AL Rookie of the Year voting and is primed to contend for the award once again. 

Mountcastle ranked in the 65th percentile in hard-hit rate. He is not an exit velocity guy, but the outfielder consistently makes hard contact. He excels especially at staying through the center of the field, hitting the ball up the middle over 40 percent of the time.

Perhaps the most important part of Mountcastle's development is his growing plate discipline. He had 130 strikeouts and just 24 walks in the minors in 2019. But he walked more and struck out less in his rookie campaign, which is a good sign for continued progression at the dish.

The 2015 first-round pick also has tremendous speed for a guy his size. The 230-pound Mountcastle ranked in the 78th percentile in sprint speed. He was not much of a thief in the minors (just four stolen bases between Double-A and Triple-A) but could be someone who takes the extra base and is a strong baserunner.

Mountcastle has demonstrated success in the majors in a fairly sizable sample. That matters, even if the O's could struggle to get wins in 2021.

The Miami Marlins can be optimistic about the young arms in their rotation, especially after Sixto Sanchez's impressive debut in 2020.

Miami acquired Sanchez from the Philadelphia Phillies in the J.T. Realmuto trade. He promptly dominated Double-A ball in 2019 before getting a shot in the Marlins rotation last summer.

Sanchez made an immediate impact. He had a 3.46 ERA in seven starts, finishing seventh in the NL Rookie of the Year voting. The 22-year-old ranked above the 82nd percentile in both expected slugging (xSLG) and expected wOBA (xwOBA), which are excellent indicators given his stuff.

Everything starts with his changeup. Opponents hit just .148 with a .189 xwOBA against Sanchez's changeup, a pitch he can deploy at any time.

That plus off-speed offering is so important because of Sanchez's velocity. He averaged 98.5 mph with his fastball and can easily get into triple digits. Plus, Sanchez can keep hitters honest with other decent breaking stuff.

The key for Sanchez will be generating more swings and misses. He ranked in just the 36th percentile in whiff rate, which is a bit underwhelming given his pitch arsenal.

However, Sanchez is just 22 years old. He has advanced command for someone his age, and the fastball-changeup combination makes for an incredible high ceiling.

The Atlanta Braves desperately needed a lift in the rotation last season. Ian Anderson was there to provide that lift.

Anderson was terrific in six regular-season starts, posting a 1.95 ERA and striking out 41 in 32.1 innings of work. His brilliance carried into October, as the 22-year-old had a 0.96 ERA in four postseason starts.

The right-hander is ready to take on a bigger role in Atlanta's rotation in 2021. 

Much like Sixto Sanchez, Anderson owes much of his success to an excellent fastball-changeup combination. He averaged over 94 mph with the fastball in 2020, with opponents hitting just .104 and whiffing at 39.8 percent of his changeup offerings. 

Getting soft contact and missing bats are two keys to being a successful starter. Anderson does both quite well. He ranked in the 99th percentile in both expected slugging (xSLG) and barrel rate. Unlike Sanchez, Anderson missed more bats than the average in his debut, ranking in the 66th percentile in whiff rate in 2020. 

The intangibles should also be noted. Anderson showed incredible poise—especially in Game 2 of the NLCS, pitching out of multiple early jams against a tough Los Angeles Dodgers lineup. 

Atlanta should be a top contender in the NL, with Anderson serving a crucial function in the middle of the Braves rotation.

Ke'Bryan Hayes needed all of 24 games to lead the Pittsburgh Pirates in WAR in 2020. Part of that is the Pirates just being a really bad baseball team. But there is no denying Hayes' absurd talent.

The 24-year-old slashed .376/.442/.682 with five homers, seven doubles, two triples and a 2020 OPS+. He had an average exit velocity of 92.8 mph and a hard-hit rate of 55.4 percent. Those are legit stats, even if they occurred in a small sample size. Not to mention, Hayes is tearing up spring ball with a 1.310 OPS in his first 11 games. 

Hayes' spectacular success at the plate is so astonishing in part because he was more renowned for his defense. He earned a near-perfect 75 fielding grade from MLB.com, with exceptional range and good hands at the hot corner. 

Indeed, Hayes showcased his defensive brilliance in 2020. He ranked in the 85th percentile in outs above average and recorded four defensive runs saved.

The Texas native also has upside as someone who can steal bases. Hayes ranked in the 79th percentile in sprint speed and swiped 12 bags at Triple-A in 2019.

Pittsburgh is likely going to be one of the worst teams in baseball. But Hayes is undeniably one of the top young talents in the game.

Tampa Bay Rays outfielder Randy Arozarena put baseball fans on notice in October.

Arozarena set MLB records for most home runs (10) and hits (29) in a single postseason. He was consistently the most dangerous hitter in Tampa Bay's lineup, mashing everything in sight and showing power to all fields.

However, the breakout postseason star's season deserves a bit of a rewind. 

The 26-year-old missed the first month of last season after contracting COVID-19. He gained 15 pounds of muscle in quarantine thanks to 300 pushups a day as well as a diet mostly consisting of chicken and rice. The added bulk paid dividends.

The Cuba native was a star when he returned in late August, slashing .281/.382/.641 with seven homers, four stolen bases and a 179 OPS+ in 23 games. It was an appropriate precursor to a spectacular postseason run.

What will Arozarena do for an encore?

The Rays will need to produce more offense in 2020. Arozarena can be a sparkplug with his power and especially his speed. He ranked in the 93rd percentile in sprint speed and took the extra base 60 percent of the time.

There will be big expectations for Arozarena especially after his outstanding October. But he has the tools and track record to be an All-Star in 2021.

All stats obtained via Baseball Reference, Baseball Savant or FanGraphs, unless otherwise noted. Spring training statistics accurate as of March 22.