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2021’s Biggest Breakouts


Not all stars find it right away, and each MLB season, new stars burst onto the scene out of the blue. Mariano Rivera broke out in ’96 and became the greatest reliever in baseball history. Greg Maddux had 5.50+ ERA’s every season until his ’88 breakout year. In 2021, it’s been no different. So, let’s take a look at the biggest breakout by team.

Baltimore Orioles – Cedric Mullins

This was a tough one, because both John Means and Cedric Mullins have burst on to the scene to become all-star caliber players, but Mullins has arguably shined the brightest. The 2015 13th rounder made his debut in 2018, but didn’t get a substantial role until this year. In 2021, Mullins has raked batting .314 with 13 home runs, a 3.1 WAR, and a 154 OPS+ (league average is 100). With this Mullins will likely find himself a member of the 2021 American League All-Star Team.

Boston Red Sox – Matt Barnes

Barnes has been a reliable reliever for Boston since 2016, but in 2021 he’s taken his game to another level. The 2018 World Champ has posted a 3.07 ERA, a 1.66 FIP (Fielding Independent Percentage), 48.1 K% and a 1.5 WAR. Those are some serious numbers.

New York Yankees – Jonathan Loaisiga

This was tough as the Yankees are lead almost entirely by veterans, but Loaisiga was the clear pick. Loaisiga has been on the Yankees roster since 2018 but hadn’t really gotten it going until this season. The Nicarauguan born pitcher has posted a 1.63 ERA with a 1.0 WAR in 30 appearances for a Yankees bullpen that has been ravaged by injuries.

Tampa Bay Rays – Tyler Glasnow

Glasnow’s had a rocky road to success. After being a highly ranked prospect most of his career, Glasnow showed flashes of being an ace in 2019 before injuries took over. Although he has sustained another injury in 2021, you can be certain Glasnow is a star in the making. In 14 starts he has posted a 2.66 ERA, 2.77 FIP, 36.2 K% and 2.5 WAR. It must be noted though, that Glasnow admitted to using foreign substances in an interview following his injury.

Toronto Blue Jays – Vladimir Guerrero jr

Son has matched father. After two underwhelming years from the Blue Jays young star and a fantastic Home Run Derby performance, Vladdy time is finally here. Junior has hit .337 with a league leading 23 bombs with a 196 wRC+ and a 4.1 WAR. Those are MVP numbers for the newest superstar.


Chicago White Sox – Carlos Rodon

The 3rd overall pick in 2014 by the White Sox had never lived up to the hype, even to the point of being non tendered in last offseason. Rodon has flipped the script in 2021 with a no hitter, 1.83 ERA, 2.39 FIP, 2.8 WAR, 36.6 K%. The former NC State ace is officially a beast.

Cleveland Indians – Aaron Civale

Civale showed flashes of all-star potential in 2019 and was solid in 2020, but in 2021 Civale has taken his game to the next level. Civale has posted a 3.32 ERA along with a league leading 10 wins to help the Indians remain contenders even with all the injuries they have endured.

Detroit Tigers – Spencer Turnbull

Most expected the Tigers to be bad in 2021, but no one expected the Tigers to have pitching as a strength. Turnbull has posted some solid numbers in the past but in 2021 he’s truly stepped it up. In 9 starts Turnbull has posted a 2.88 ERA, a 2.94 FIP, 1.5 WAR and a 21.9 K%. The future in Detroit is bright.

Kansas City Royals – Scott Barlow

Barlow has emerged as a really good relief pitcher for Kansas City and no one has been talking about him. Barlow’s posted a ridiculous 2.04 ERA, 2.15 FIP, 1.1 WAR and a 33.6 K% line for the Royals and might fight for an all-star spot.

Minnesota Twins – Byron Buxton

Buxton has been a solid center fielder for the Twins with great defense since being one of baseball’s top prospects. His bat though has been awakened in 2021 with a ridiculous line of a .369 AVG, 10 home runs, a 217 wRC+ and a 2.7 WAR in limited time. If he can stay healthy, he might receive some MVP votes even for a lackluster Twins team.

Houston Astros – Lance McCullers jr

He’s stayed healthy (knock on wood). For the first time ever he’s been healthy. Most of the Astros team is established veterans. He’s posted a 2.90 ERA. 25/8 K% and a 4-1 record for the very scary Astros team.

Los Angeles Angels – Jared Walsh

He made our 2020 All-Rookie team, but he’s taken his game to a new level in 2021 for the (somehow) solid Angels team. Walsh has put up a .290 batting AVG, 18 home runs, a 152 wRC+ and a 2.2 WAR. It’s safe to say that he’s got a bright future.



Oakland Athletics – Sean Manaea

Matt Olson has been a beast in 2021, but he’s posted great numbers in the past, but there have been guys that have broken out more. One of those guys is Sean Manaea who has gone from solid starter to a true ace, with a 3.01 ERA, 3.07 FIP, 2.1 WAR, and 2 shut outs. He’s going to be great for a while.

Seattle Mariners – Yusei Kikuchi

The former Nippon Professional star signed a hefty 3-year deal back in the 2019 offseason. After 2 bad seasons in 2019 and 2020, he’s finally started to live up to the deal posting a 3.46 ERA, 25.3 K%, 0.8 WAR. He may not be elite, but Yusei is on his way.

Texas Rangers – Isiah Kiner-Falefa

Kiner-Falefa has become one of the better defenders in the league since his debut in 2018, and he has really come into his own as a hitter in 2021. He has hit .289 with 6 home runs, with a 103 wRC+ and a 2.1 WAR. Although he’s still not a top tier hitter he’s becoming a much more complete player.

Atlanta Braves – Austin Riley

Riley showed a ton of promise in his 2019 rookie season but hadn’t really built on that until this season. Riley has truly broken out with a .273 batting average, 12 home runs, a 123 wRC+ and a 1.0 WAR. Riley should be a cornerstone for the Braves for the future.

Miami Marlins – Pablo Lopez

Lopez has really emerged as an ace-level pitcher for South Beach. After a rocky 2019 season, and a solid 2020 season Lopez has taken over in Miami. A 2.86 ERA, 3.27 FIP, 1.8 WAR and 9.0 K/9 are what we’ve seen from the Venezuelan born pitcher. Along with Sixto Sanchez, Sandy Alcantara and Trevor Rogers, this rotation is going to be good for a long time.

New York Mets – Taijuan Walker

The Mets offense has been ravaged by injuries and severely underperforming yet they sit first in the NL East because of their fantastic pitching. Taijuan has been around for a while but he has taken his game to another level in 2021 with a 2.42 ERA, 3.01 FIP, 2.0 WAR and a 6-3 record. If their elite staff keeps it up, the loveable losers are on the right path.

Philadelphia Phillies – Zack Wheeler

The Cy young candidate has finally lived up to his 6th overall pick potential. Wheeler was really good in 2018 and 2020, but he’s taken over as the ace of the staff in Philly in 2021. He’s pitched to a 2.36 ERA, a 2.44 FIP, a 3.5 WAR and a 11.05 K/9. He has become another star who broke out after he left the Mets, and now is one of the better pitchers in the league.

Washington Nationals – Erick Fedde

Fedde has been in the Nationals rotation since 2017, and took steps forward every year with a 5.10 ERA over that span. Despite the Nationals usually elite rotation struggling in 2021, Fedde has been one of the only bright spots. He’s pitched to a 3.33 ERA, a 3.86 FIP, an 0.9 WAR and 8.6 K/9.

Chicago Cubs – Ryan Tepera

The former Blue Jays reliever received an MVP vote by accident in 2020 but in reality, he’d just been a decent pitcher. He’s truly stepped it up in 2021 though, with a 2.02 ERA, a 2.49 FIP, a 1.0 WAR and 10 K/9 along with being the May NL reliever of the month. The Cubs bullpen has been ELITE in 2021, and Tepera’s been a key part of that.

Cincinnati Reds – Jesse Winker

Tyler Naquin and Tyler Mahle have also broken out this year, but Winker’s become one of the top hitters in the National League. A .333 Batting Average, 17 home runs, a 170 wRC+, and a 2.6 WAR are what we’ve seen from Winker this year, and it looks like there’s a lot more to come from the 27-year-old.

Milwaukee Brewers – Freddy Peralta

Corbin Burnes and Brandon Woodruff have also became elite all-star pitchers, but they had already established themselves as good pitchers. Peralta has posted a 7-2 record, with a 2.11 ERA, a 2.80 FIP, while striking out 12.7 K/9 and only allowing 4.1 H/9. It’s safe to say that the Brewers rotation is one of the best and Peralta stepping it up has been a big part of it.

Pittsburg Pirates – Richard Rodriguez

Adam Frazier and Bryan Reynolds are both all-stars, but have been good in the past. Rodriguez has burst onto the scene in 2021 with a 1.84 ERA, 2.21 FIP and 9 saves for a poor Pirates team. His breakout season has made him a major trade piece for the rebuilding Pirates.

St. Louis Cardinals – Tyler O’Neill

The Cardinals have been underperforming this season due to some injury issues, but one guy who’s really shined has been the gold glover Tyler O’Neill. Along with his elite defensive play O’Neill has hit .276 with 15 home runs, a 146 wRC+ and a 1.9 WAR. If the Cardinals can bounce back O’Neill will be a big part.

Arizona Diamondbacks – Carson Kelly

Kelly came to Arizona in the Goldschmidt trade a few years ago, and hadn’t performed too much since then. Kelly has hit .260 with 8 home runs, a 132 wRC+ and a 1.5 WAR. The rebuilding Diamondbacks may have found their guy for the future.

Colorado Rockies – Austin Gomber

The biggest return in the Arenado trade has been one of the biggest breakouts for a team that has played boring and just overall poor baseball. The 27-year-old has posted a 3.68 ERA and a 3.63 FIP, with a 1.5 WAR and a 24 K%. Could he be the ace of the future for this rebuilding Colorado team? Time will tell.

Los Angeles Dodgers – Chris Taylor

The Dodgers team is almost entirely made up of established veterans so picking a true breakout guy was tough. Chris Taylor has had a bigger role this year than in most due to injuries to Cody Bellinger. He’s hit well batting .270 with 10 home runs, a 142wRC+ and a 2.3 WAR. The Dodgers at full strength are the best team in baseball, and Taylor has made them even better.

San Diego Padres – Joe Musgrove

This was an easy one. The Padres knew who they were trading for last offseason when they acquired Musgrove from the Padres, but they didn’t know he’d be this good. Musgrove has put up a 2.28 ERA, an 3.11 FIP, 11.2 K/9, and a 1.8 WAR along with throwing the first no hitter in franchise history.

San Francisco Giants – Kevin Gausman

Another cy young candidate having a breakout year to rap it up. Gausman was given a qualifying offer last season to the surprise of many fans, but he’s more than played up to it. Gausman has pitched to a 1.51 ERA, a 2.37 FIP, a 2.9 WAR, a 30.5 K%, and an 8-1 record for the first place Giants.

In your opinion who’s been the biggest breakout this year?