Prospects, rookies, and hyped up sophomores can make or break a fantasy season. Younger players generally have more fanfare among analysts and fantasy managers can therefore suffer from “shiny new toy syndrome.” This means we sometimes get too swept up in what some players could become, making a risky pick instead of drafting the “boring” known quantities. Therefore, it’s important to know what we’re getting into with these guys.

Below is a breakdown of second-year hitters for the 2021 fantasy baseball campaign.

Dominate with our award-winning fantasy baseball draft software

Luis Robert (OF – CWS)
Robert was the consensus favorite for American League Rookie of the Year honors entering 2020. His rookie year turned out to be two different stories, as the 23-year-old absolutely erupted onto the scene before struggling badly down the stretch. We’ll start by recapping the good version of Robert, who hit .298/.348/.612 with 10 of his 11 homers through the end of August. Once the calendar flipped to September, however, he immediately fell off and hit just .136/.237/.173 to close out 2020.

Robert has always been a high-end “real life” prospect thanks to his baserunning and defensive prowess, which gives him a very high floor as a player. However, it wasn’t until his 2019 minor-league power breakout where Robert became an untouchable dynasty league asset. As you can see below, Robert can generate 30-HR power despite a swing that borders on “effortless”:

Luis Robert rookie season off to an electric start:

.351 BA
.981 OPS
2 HR
1 SB
Hit leadoff this weekend

I don’t have him in enough leagues and I officially have FOMO pic.twitter.com/yfdeDmuOzB

— Brendan Tuma (@toomuchtuma) August 3, 2020

Yet it wasn’t difficult to see where things could go wrong for him as the summer went on. Robert was swinging at everything last year. His 57.3% swing-rate was the second-highest in baseball. He ranked in the top-four of the league when it came to swinging both inside the zone and outside. Combine this with a bottom-two percentile whiff rate, and eventually, pitchers figured out the book on Robert.

Major League Baseball is a game of adjustments, though, and it’s now on Robert to adjust back. Becoming more selective would be a good place to start. A swing-happy approach isn’t what propelled Robert to that early success. Swinging at the right pitches is what did the trick.

He has all the physical tools to be a true superstar with a better approach at the plate. Therefore, it’s important to remember that Robert has just 56 big-league games under his belt, and from 2017-19 he only appeared in 200 minor league contests due to injuries. This is a young player who is still figuring out who he is as a ballplayer and we certainly shouldn’t write him off.

Even if it comes with a weak batting average and prolonged slumps, Robert’s 25/25 skillset will keep him very fantasy relevant for years to come. He’s a high-variance player entering ’21 drafts. I’ll certainly be on the lookout for any offseason stories highlighting a change in approach.

Ke’Bryan Hayes (3B – PIT)
Thank goodness Ke’Bryan Hayes didn’t debut until September 1, when a lot of the fantasy community began shifting their focus to football. Otherwise, his 2021 average draft position would be even more out of control than it’s already going to be. A first-round pick of the Pirates back in 2015, Hayes was almost exclusively known for his glove coming through the minors. Yet after a 24-game sample in the big leagues, it looks like he could follow in the footsteps of Nolan Arenado and Matt Chapman as “glove-first” third base prospects who eventually erupted offensively.

Hayes hit a robust .376/.442/.582 with five homers, 11 RBIs, and 17 runs scored in those 24 games. Now before we get completely carried away, let’s note that the .376 batting average was fueled by a 5-for-5 performance on the second-to-last day of the season. According to Baseball Savant, Hayes’ xBA came in at an even .300. This falls more in line with his career minor league average of .279, though we need to make note that Hayes started hitting the ball with more authority in the second half of 2019.

This carried over to his major league performance in September, where Hayes put up a 92.8-mph average exit velocity and a 55.4% hard-hit rate. Both of these would’ve ranked within the top-15 of baseball over the course of a full season. The one area we could nitpick Hayes’ game is a high ground-ball rate (47.7%). A lack of fly balls will likely limit his homer potential unless he undergoes a swing change. Hayes is talented enough to continue making adjustments, however, as he’s already a much different hitter than he was entering ’19.

With Hayes’ current skill set, I see him hitting around .280 with 15-20 homer upside, but with many doubles and even a handful of stolen bases (kind of like an early-career Manny Machado). Of course, his talent gives him the upside to be much more once he gets more experience under his belt. The 23-year-old is already going within the top-140 in offseason NFBC drafts, but I’d be comfortable selecting Hayes closer to the top 100. He could be an outright steal in casual leagues.

Ke’Bryan Hayes is 4-for-4 with two doubles tonight, raising his average to .363 for the year to go along with a 1.064 OPS.

Came to the majors as a defense-first prospect, but he’s been all around great. pic.twitter.com/Kmlds7aH73

— Brendan Tuma (@toomuchtuma) September 27, 2020

Kyle Lewis (OF – SEA)
There’s this misconception within some circles that Lewis “came out of nowhere” in 2020. He didn’t. Lewis was the 11th overall pick of the 2016 amateur draft, and Baseball America pegged him as the 34th best prospect entering 2017. Unfortunately, the young outfielder suffered a devastating knee injury soon after turning pro. His prospect shine faded over the next few years, but Lewis still made it to the majors for a rebuilding Mariners squad in September 2019.

Lewis popped in those 18 games, hitting six homers and five doubles to go along with an .885 OPS. We didn’t have any actual stats to examine when MLB resumed summer camp in July 2020, but every report on Lewis came with rave reviews. Then he homered off Justin Verlander on Opening Day. Then he kept homering and eventually won American League Rookie of the Year honors.

This isn’t to say Lewis’ season was perfect. Far from it, actually. For all the love he was shown during 2020, Lewis finished with an .801 OPS. He faded hard down the stretch, as both his strikeout tendencies and whiff rate eventually caught up with him. Through August 31, Lewis struck out in 24.8% of his at-bats. That figure rose to 37.1% in September. This isn’t to say Lewis can’t adjust back, but strikeouts have been an issue his whole career.

While the 25-year-old was an amazing value in 2020 fantasy baseball leagues, we shouldn’t go right back to the well, especially at a higher cost and a rising number of concerns in his offensive profile.

Check out all of our 2021 fantasy baseball draft prep content

Alec Bohm (3B – PHI)
Like fellow third baseman Hayes, Bohm is another young stud who we will have to pay a premium for in 2021 drafts. The 24-year-old is already being selected right outside the top-100 in NFBC leagues. Yet there’s a case to make for taking him closer to 75th overall.

Bohm’s surface-level stats are fantastic; he hit .338/.400/.481 in his first 44 big-league games, which made him a finalist for National League Rookie of the Year honors. A strong hit tool was the foundation of Bohm’s high-end prospect status. He certainly backed up that reputation in 2020, though it didn’t come with as much power as one might’ve guessed. Bohm hit just four homers during his initial MLB impression, but he also totaled 11 doubles.

His .144 ISO was a big drop from the .213 mark he put up across three minor league levels in 2019. Of course, that could be attributed to Bohm adjusted to big league pitching, and the fact that he hit .338 shows that he wasn’t exactly overmatched. Bohm’s approach at the plate is one to believe in. His fantasy value will come down to whether or not he can tap into that power a bit more, as well as if he can reach double-digit stolen bases. I’d want at least one share of him if playing in multiple leagues.

Jake Cronenworth (2B – SD)
Jake Cronenworth was one of the best waiver-wire pickups of the 2020 fantasy baseball season, an out-of-nowhere “Statcast darling” who nearly went on to win NL Rookie of the Year. Cronenworth’s base stats over his 54-game season were more than useful for fantasy managers: a .285 average to go along with four homers, three steals, and an .831 OPS. This production came with some exceptional hot stretches and plenty of positional versatility.

However, I’d be lying if I said those end-of-year numbers are all that special. Cronenworth has a skillset “real life” baseball managers dream of — a versatile speedster who rarely strikes out and has some unexpected pop. Several of his talents don’t translate the same way to fantasy, though. The Baseball Savant page looks great, as the 26-year-old ranked within the 95th percentile of xBA and xwOBA. Still, as a fantasy asset, Cronenworth seems far more useful in leagues that prioritize batting average. The Padres run as much as anyone, so we should expect 15 or so steals over the course of a full season. I’m not too confident in the game power.

Cronenworth was a great story last year, and it’s tough to say anything negative about him. I’m just not sure he’s a difference-making fantasy option. He’s going as the 148th overall pick in NFBC drafts right now. Those deeper roto leagues with a heavy emphasis placed on positional versatility and batting average are probably his best format.

Ryan Mountcastle (1B/OF – BAL)
You might’ve easily missed Ryan Mountcastle’s production if you had moved to fantasy football as of August 21. The 23-year-old slugger finally made his debut, long after many of us in the prospect world expected it to come in 2019, and he made an impact in fantasy leagues down the stretch. In 35 games, Mountcastle managed to hit .333/.386/.492 to go along with five homers and 23 RBIs.

A former first-round pick, Mountcastle’s poor defense meant that he was never considered a top-50 prospect by any traditional sites. However, he always hit, which led to him being named the International League (Triple-A) MVP in 2019.

The last two seasons we’ve seen Mountcastle, both in the minors and majors, he has produced. His underlying metrics aren’t much to write home about, which does give me some pause on aggressively drafting him this season. I’d shy away from his ADP of 142 in NFBC drafts right now, but I could see targeting him in more casual leagues where some league mates may not realize his recent track record of success.

Gear up for your draft with our MLB Draft Simulator

Subscribe: Apple Podcasts | Spotify | Google Podcasts | Stitcher | SoundCloud | iHeartRadio

Beyond our fantasy baseball content, be sure to check out our award-winning slate of Fantasy Baseball Tools as you navigate your season. From our Trade Analyzer – which allows you to instantly find out if a trade offer benefits you or your opponent – to our Waiver Wire Assistant – that allows you to quickly see which available players will improve your team, and by how much – we’ve got you covered this fantasy baseball season.

Brendan Tuma is a correspondent at FantasyPros. To read more from Brendan, check out his archive and follow him @toomuchtuma.