Grading 5 MLB second-half breakouts from real to fake

It's commonplace around this time of year for young stars to really break out in MLB. Whether it's a rookie who has been grinding for months and is just finding his groove, or if it's a new call-up who comes out of the gate thwacking, the MLB is chock full of ascendant talent.

For this exercise, we will distill five of the most prominent and productive rising stars in MLB and determine which of them are "real" and which of them are "fake" — or more accurately, which breakouts do we believe are most sustainable.

From a Rookie of the Year candidate on MLB's best team to an unheralded prospect making waves in South Beach, there are a lot of interesting candidates for a list like this. Hopefully this five names strike a cord and paint an accurate portrait of baseball's next generation.

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5. OF Isaac Collins, Milwaukee Brewers

Isaac Collins is one of several young stars propelling the Milwaukee Brewers to the best record in MLB. It has been an improbable season all around for the Brewers, who were expected to take a step back after another quiet offseason. Milwaukee simply does not pay to keep top-shelf stars like Corbin Burnes, which can make it difficult to hang with the National League's upper echelon. At least, you'd think it would.

But the Brewers continue to run the NL gauntlet with ease, in no small part due to Collins and an impressive array of up-and-comers. Collins has done a little bit of everything for the Brewers, hitting for average, drawing walks, stealing bases (16 on the season) and providing above-average defense in left field. While not a natural slugger, Collins has found a way to ratchet up his power down the stretch. It may not manifest often in the home run category, but when it comes to shooting doubles into the gap and driving home clutch runs, Collins in a menace.

He's clearly a very solid all-around contributor, and Milwaukee can expect him to contribute for years to come, but we might want to pump the breaks on any premature coronations. Collins is a very smart hitter, he sees the zone exceptionally well, but he's also a 28-year-old rookie with a modest expected average (.255) and a low barrel rate (19th percentile), suggesting a low quality of contact and a bit of good luck on his side. He's still fairly young, but unlike other Rookie of the Year candidates, Collins will soon turn 30, so his room for true growth is presumably limited.

Verdict: Questionable

4. 1B Kyle Manzardo, Cleveland Guardians

The Cleveland Guardians are making a strong push for the final Wild Card spot in the American League, with Kyle Manzardo's emergence in the cleanup spot serving them quite well in that pursuit. Manzardo's OPS is over 100 ticks better since July 1 than it was beforehand; he's ratcheting up the power, generating more consistent contact, and limiting strikeouts to the best of his ability.

For the most part, this all checks out in the metrics. Manzardo is slightly underperforming his "expected" average and slugging, so if anything, his numbers should look even better. He's a classic lefty in that his numbers against right-handed pitching are especially encouraging (.817 OPS) compared to more muted production in lefty-on-lefty matchups (.676 OPS).

At the very least, Manzardo should profile as a dependable source of power against righties for the remainder of his rookie contract. But in terms of projecting his long-term ceiling, it's fair to wonder how much more Manzardo has in the tank. Southpaws neutralize him almost completely, and he's still a high-strikeout hitter and a subpar defender at first base, which is not exactly the sexiest archetype in MLB.

Cleveland needs Manzardo's power and he should be able to provide 20-plus home runs on an annual basis, but account for the ebbs and flows inherent to boom-or-bust offensive "stars" whose only value is derived from slugging.

Verdict: Proceed with caution

3. OF Jakob Marsee, Miami Marlins

Jakob Marsee was the Miami Marlins' No. 8 prospect at the time of his call-up. He was essentially tasked with filling in for injured All-Star Kyle Stowers, a tall task for a 24-year-old with zero MLB experience beforehand. The results? Stunning, to be frank. Marsee was productive in Triple-A and worthy of a promotion, but nobody could have seen this coming. Not only has Marsee been Miami's best hitter since his debut on Aug. 1, but he ranks 19th in all of baseball with a 155 wRC+. He's one of the best hitters in baseball, period.

Skepticism is probably the natural response to such a sudden and unexpected breakout, but it's hard to poke holes in what Marsee is doing at the plate right now. Sure, he probably won't maintain his current rate of slugging, but it's not like Marsee wasn't a power threat in the Minors. He has a 10.4 percent walk rate, and ranks near the top of the league (albeit in a small sample size) in both chase percentage (18.0) and squared-up percentage (19.2), which means he is making intelligent swing decisions and generating consistently solid contact.

Marsee has thus far proven quite adept with his glove, covering significant ground and showcasing a canon-like arm from the deepest parts of centerfield. He also has 10 stolen bags, and he's probably the best-hitting rookie in the National League this season. The only reason he won't win Rookie of the Year is a lack of reps. It's still early, so variance could become a factor later on, but right now, Marsee's breakout is easy to buy.

Verdict: Heck yeah, brother

2. C Kyle Teel, Chicago White Sox

Kyle Teel was the centerpiece of the Chicago White Sox' return package in the Garrett Crochet trade. An ex-member of the 'big four' prospects in Boston, alongside such names as Roman Anthony, Marcelo Mayer and Kristian Campbell, we can hardly call Teel's success surprising. But it's a breakout all the same, as the 23-year-old already looks the part of Chicago's best player and franchise cornerstone.

He arrived late in the season, debuting on June 6, and has produced exceptional results the whole way through. That said, a dig into the metrics does unearth a few mild red flags. Not serious long-term concerns for a prospect of Teel's caliber, but perhaps reason to take this immediate success with a grain of salt.

Teel is not producing much hard contact (37.8 percent hard-hit rate, 9.8 percent barrel rate) and he offsets a high walk total with a healthy chunk of strikeouts. Generally, Teel sees the zone well and is smart with his swings, making up for limited pop with a knack for splitting the gaps and hitting to all areas of the field. He's not a speed demon, but he's quick enough to apply pressure on a defense once he's in motion. Expect a lot of extra-base hits from Teel before his career is done.

He's also struggling a bit with his duties behind home plate, in the 18th percentile for blocking and the 59th percentile for framing. Those are improvable areas for a young catcher, but since catchers typically experience swift regression athletically and don't hit for a ton of power (save for, like, Cal Raleigh), it's fair to wonder of Teel is merely a solid, above-average backstop, rather than a true lodestar for a fledging White Sox lineup. Even so, a catcher who can produce even solid numbers at the plate is a rare enough gift, and Teel is one of the youngest (and certainly the most coveted) of the players on this list.

Verdict: Real deal Teel

1. OF Tyler Soderstrom, Athletics

How can you not be romantic about this Athletics team? The record is bad. The ownership group? Awful. The ballpark situation? Yikes! But despite all the odds being stacked against them, this group is showing signs of imminent contention. There's something to be said for developing and sustaining a premier pipeline of young talent — one that will only churn out more stars after a trade deadline that saw MLB's No. 3 overall prospect, Leo De Vries, land in Sacramento.

The A's will be good sooner than later, mainly due to an explosive offense. We needn't even mention Nick Kurtz, who has put together one of the most dominant rookie campaigns in recent history since his call-up. We've also got Shea Langeliers gunning for 30-plus home runs as a catcher. Not far below them on the organizational ladder, you land on 23-year-old Tyler Soderstrom, who has fully broken out for the A's.

Soderstrom began his career as a catcher and spent a lot of last season at first base. Now he's manning left field, and while he's not a great defender, Soderstrom is a major athlete who is getting better at a relatively new position. Factor in that versatility with the lefty's substantial prowess at the plate, and the A's may have a bonafide star on their hands.

There aren't a ton of more beautiful swings in baseball than Soderstrom when he's raking. He gets it through the zone quicker than you'd think for such a tall dude, and it generally leads to the baseball leaping off his barrel with a purpose. Soderstrom occupies the 87th percentile for hard-hit rate and the 83rd percentile for exit velocity. Over the past few months, he has cut down on strikeouts and found ways to hit for contact without sacrificing his raw power. I'm not saying Soderstrom is going to hit .315 for the rest of his career — he won't — but the process is improving constantly. You can see him getting better almost in real time.

As the A's build toward a bright future, be it in Sacramento, Las Vegas, or Atlantis, expect Soderstrom's skyward ascent to continue. He's an extremely fun and an extremely special player.

Verdict: Yes