Fantasy baseball breakouts: Is this the season for Arenado, Betts?

Star these potential breakouts on fantasy football draft sheets, because you'll want them on your team.

Too often, the definition of a fantasy breakout candidate is confused with a sleeper. A sleeper is someone who seemingly comes from nowhere, and definitely comes from deep in the overall rankings. A breakout player, on the other hand, is someone who has had success and enters the current season with high expectations. What makes him a breakout is the belief that he will surpass those expectations and vault himself into a new class of player.

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Both breakouts and sleepers are undervalued, but breakouts are potential superstars while sleepers simply present an opportunity to pick up excess value. Breakout players are typically selected in the middle rounds, while true sleepers aren’t coming off the board until your draft hits pick No. 100.

It’s important to clear that idea up as we head into staples week here on SI.com. What’s staples week? Well, every year, in every sport, everyone who writes about fantasy will produce a list of breakouts, sleepers and busts. We’re doing that this week, beginning with the breakouts. These are the players you’re going to want to star on your cheat sheets before draft day. After posting monster seasons, they’re going to find themselves on a ton of fantasy championship teams.

Nolan Arenado, Colorado Rockies

I’ve written more words about Arenado than perhaps any other player this winter, and with good reason. The third-year player is my top breakout candidate this season. He hit a robust .287/.328/.500 with 18 homers and 34 doubles in 467 plate appearances last year. Had he been healthy for the entire season, he undoubtedly would have reached 20 homers, and may have pushed 40 doubles. Every possible measurable points to him taking another step in 2015.

First of all, Arenado will turn 24 years old in April. He’ll likely gain some natural power progresses into his mid-20s, and he showed just how much pop he already has last year. His average true home run distance of 408.9 feet was better than that of Edwin Encarnacion and George Springer. Arenado’s HR/FB ratio also jumped to 11.4 percent last year, while he hit fly balls more frequently than he did in his rookie season. He’s going to approach, and I believe surpass, the 25-homer mark this year.

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Last season, Areanado had just a .294 BABIP despite a 20.6-percent line-drive rate and 19.9-percent hard-hit rate that ranked 34th in the majors. He did have a high popup rate, but his xBABIP was still .305, suggesting he was unlucky on batted balls. If that turns around this season, he should have improved batting average and OBP. Like most players on the Rockies, Arenado did his best work at Coors Field. He slashed .303/.344/.584 with 16 of his 18 bombs at home. That may seem like a red flag, and indeed, Arenado could leave you wanting more in weeks that the Rockies spend on the road. Still, he’s getting his 81 games at Coors this year, and he figures to rake in the high altitude.

More than anything, this is a bet on an already-very-good player becoming a star as he enters his mid-20s. Arenado has nearly 1,000 major league plate appearances under his belt. With the combination of experience, youth and talent at his disposal, he’s on the verge of becoming the league’s next great all-around third baseman.

• ​FANTASY: BREAKOUTS | SLEEPERS | BUSTS

Mookie Betts, Boston Red Sox

Betts is another favorite of the SI.com fantasy department this year. If you’re buying Betts along with us, you have to be a true believer. The Red Sox have a crowded outfield, with Hanley Ramirez, Shane Victorino, Rusney Castillo, Allen Craig, Daniel Nava, Brock Holt and Jackie Bradley all in the mix. Betts, however, deserves to be in there every day, and not only because he proved last year he can play above-average center field at the very least. Betts is also a potential star at the plate.

There really doesn’t seem to be anything Betts doesn’t do well with the bat. He spent approximately one-third of the season at all of Double-A, Triple-A and the majors last year. In that time, he hit 16 homers and swiped 40 bases in 677 plate appearances. His batting average decreased at each level, and that may sound like a red flag until you see that he hit .291/.368/.444 with the Red Sox. Betts posted a 9.9-percent walk rate as a 21-year-old without any major league experience. He racked up 1.9 fWAR in just 52 games. He swung at less than one-fifth of pitches outside the strike zone. In other words, he flashed power, speed, plate discipline, and the ability to hit for a high average in the same year he could first legally buy a beer.

The Red Sox would be doing everyone who enjoys baseball, except perhaps fans of other AL East teams, a disservice if Betts isn’t in the lineup most every day.  Steamer projects Betts to hit eight homers and steal 15 bags—in just more than half a season. Everything from his 52-game sample last year to his minor league track record to projection systems to traditional scouting says Betts is on track for a big season. Thanks to the uncertainty surrounding his playing time, you can still get him at a discounted price. This is the last season that will be the case.

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Starling Marte, Pittsburgh Pirates

Marte has been an everyday major leaguer for each of the last two seasons. In that time, he has hit .286/.349/.447 with 25 homers and 71 steals. That may lead some of you to say that he has already broken out, and, to a certain degree, you're right. Marte is already considered a top-20 outifelder in the majors, and is widely recognized as a key component of the Pirates’ back-to-back playoff appearances. The bet here is that there’s another level to his game that he can reach with newfound consistency in his third full year in the majors.

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In 2013, Marte got off to a blistering start and ended up hitting .291/.342/.462 with nine homers and 28 steals in the first half. After the All-Star break, however, he tapered off to .254/.346/.387 with three bombs and 13 swipes. Last season, it was the reverse. Marte struggled offensively in the first half, but was arguably the best all-around hitter in the game after the Midsummer Classic. Marte hit .348/.408/.567 with eight homers, a .426 wOBA and 178 wRC+. The Marte of the 2013 first half and 2014 second half just might be around for all of 2015.

It’s very easy to see Marte’s year-long semi-swoon spread across two seasons as the league making adjustments to his hot start. Marte finally adjusted back during the second half last year, when, according to his own manager Clint Hurdle, he quieted his head movement. Hitting a baseball is hard enough to do. It’s even harder when your head and eyes are bouncing around in the batter’s box. If the adjustments Marte made last year are substantive, he could approach 18 homers, to go along with a .280-plus batting average and 30-plus steals.

Jacob deGrom, New York Mets

This spot originally belonged to Marcus Stroman, but 24 hours after writing about his breakout potential, word broke that he tore his ACL. After putting the jinx on Hunter Pence last week, and now Stroman this week, it’d be nice if I could just stop writing, talking, or even thinking about any players I like. Alas, we have to keep on braving those waters, so let’s turn our attention to deGrom.

There wasn’t any hype about deGrom heading into last year, and, really, why would there have been? In 2013, his age-25 season, he made two starts at High-A St. Lucie, but mostly split the year between Double-A Binghamton and Triple-A Las Vegas, compiling a 4.51 ERA, 1.45 WHIP and 120 strikeouts in 147 2/3 innings. The results only got progressively worse as he moved up and, as such, he wasn’t on anyone’s radar in 2014.

Anyone who bought the deGrom hype early cashed in, as he ended up cruising to the NL Rookie of the Year award with a 2.69 ERA, 2.67 FIP, 1.14 WHIP and 144 strikeouts in 140 1/3 innings. For whatever reason, though, fantasy owners still aren’t trusting deGrom. His ADP places him just barely inside the 10th round in a typical 12-team league, and his consensus ranking on FantasyPros is 28th among starting pitchers. That suggests a community that just isn’t fully ready to believe. Let that be your path to a great buying opportunity.

The 26-year-old deGrom features a fastball that sits in the mid-90s and, had he thrown enough to qualify, would have graded as the fourth-most effective fastball in baseball, trailing only Johnny Cueto, Clayton Kershaw and Madison Bumgarner, according to Fangraphs. He got the third-most whiffs per swing on his four-seamer, with only Bumgarner and David Price getting more. So yeah, deGrom’s fastball is pretty good.

The other pitches in deGrom’s repertoire aren’t too shabby, either. He throws a curve, slider and changeup, all of which had whiff rates of 13 percent or better last season. He also features a two-seamer and a cutter, meaning he can run six different pitches up to the plate on any given day. A year ago at this time, you may not have known his name. Now, you won’t want to forget it on draft day.

Now, in honor of Marcus Stroman, let's all enjoy this gif of his nasty sinker together.

George Springer, Houston Astros

When I think about Springer, I’m reminded of an episode of The Simpsons where Bart figures out that the MLB is spying on all of America, only to have Mark McGwire show up and steal the evidence by distracting everyone with dingers.

Everyone, even the fictional characters of Springfield, loves dingers. That’s part of what makes Springer such an intriguing player in 2015. He hit 20 dingers last season in just 345 plate appearances. And when Springer hit them, he really hit them. Just ask David Priceor Aaron Harang.

In case you were wondering, that was 907 combined feet of home run right there. Springer is going to hit homers, and he’s going to hit a lot of them. It would be a disappointment if he came up short of 30, and the right mix of health and skill growth could result in a 40-homer campaign during his age-25 season. Factor in the modest, yet meaningful, upgrades GM Jeff Luhnow made to the offense, and fantasy owners can also bet on Springer’s run and RBI totals increasing this season from the pace they were at last year.

That’s the good news with Springer. Unfortunately, you’re going to have to take with it the bad, and that means a whole lot of whiffs. Springer posted a 33-percent strikeout rate last year, helping to push his batting average down to .231. He had an 11.3-percent walk rate, so he’s not nearly as much of a risk in OBP leagues, but no matter what rate your league uses, the good more than counterbalances the bad. Springer should hit at least 30 homers with 80 RBI and 80 runs, all while stealing 15-to-20 bases. You can find batting average help elsewhere. You can’t find that sort of four-category production in one player in very many other packages.

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Quick hitters

Jorge Soler, Chicago Cubs—The 23-year-old outfielder hit .292, slugged .573 and belted five homers in 97 plate appearances in a late-season promotion. He’s the Cubs prospect to own this year.

Bryce Harper, Washington Nationals—It seems silly to include a player with such a high profile in this section, but the pendulum has swung way too far in the wrong direction on Harper. No one questions the talent, and he knows better than anyone that he needs to stay healthy. If he does, a monster season is in the offing.

Jason Heyward, St. Louis Cardinals—He has yet to reclaim the magic of his 2012 27-homer season, but let’s not forget that he’s all of 25 years old. As a rule, I always trust that the Cardinals front office did the right thing.

Alex Wood, Atlanta Braves—The Braves aren’t going to be very good this year, but they will have a strong rotation, led in part by Wood. He fanned nearly a batter per inning as a starter last year and features one of the game’s best curveballs.

Carlos Carrasco, Cleveland Indians—His dominant seven-start run at the end of the season was for real. Carrasco backs up Corey Kluber in a strong Cleveland rotation, and will be a key piece of their eventual AL Central title.