One Month Into The MLB Season, Which Rookies Are Standing Out?


Plenty of rookies have taken Major League Baseball by storm through the years. Ted Williams. Mark Fidrych. Kevin Maas.

But Yermín Mercedes, the hitting machine for the Chicago White Sox, has already achieved the ultimate in baseball immortality: There’s a burger named after him.

It sounds delicious (Mercedes himself is a fan), but it can’t be as tasty as the .395/.435/.628 slash line he has posted just over a month into the season. His resulting 1.1 wins above replacement, according to Baseball-Reference.com, leads all rookie hitters, part of an impressive crop so far of 2021 newbies.

While his numbers suggest more than a bit of regression may be on its way, as you’d imagine — a .433 BABIP, for instance, and a relatively pedestrian 36.1 percent fly ball rate, meaning he’s probably not good for five home runs per month — the injuries to Eloy Jiménez and Luis Robert could keep Mercedes in the lineup for Chicago all season.

Then again, maybe when you begin the season 8-for-8, you’re capable of anything.

While the top AL hitter has been largely a power-based source of production, it’s the speed that stands out for the National League’s best rookie hitter so far: Jazz Chisholm of the Miami Marlins.

Though Chisholm went on the injured list last week with a strained hamstring, he has so far produced a strong slash line of .290/.375/.551 with four home runs, so we’re not talking about another Billy Hamilton here. But his work on the basepaths has been impressive — seven steals in seven attempts, his total tied for second in the major leagues so far.

“He’s a really confident kid, plays with a joy that I love,” his manager, Don Mattingly, said back in early April, when he named Chisholm his starting second baseman. “He’s got a smile on his face, high energy, and high talent. This guy is capable of doing a lot. He’s one of those guys that, once he puts his whole package together, this is a superstar. This isn’t like a good player, he has a chance to be a great player, and that’s what will help Jazz walk through it day in and day out.”

He does it with speed, he does it with power, and he does it with style. Just watch his Euro step celebration after hitting a home run.

The regression gravity isn’t nearly as strong with Chisholm, provided he returns to the field soon. He’s hit the ball to all fields, and his BABIP has been high, but that’s to be expected when you run like he does. He’s playing excellent defense at second base, and he looks like both a future star and someone who will be in the conversation for an All-Star bid. 

Other standout hitters include Colorado catcher Dom Nuñez, who has five home runs and a .923 OPS in 18 games; the ode to contact hitting that is the White Sox’s Nick Madrigal (.313 batting average, three strikeouts all season in 88 plate appearances); and Cardinals outfielder Dylan Carlson, a power/speed combo with an .810 OPS for St. Louis so far.

Among rookie pitchers, the most impressive hasn’t been one of the big names entering the season. Trevor Rogers of Miami leads major league rookies in pitcher WAR with 1.2, powered by 33 innings of 1.91 ERA production. Rogers has outdueled pitchers like Jacob deGrom this season, using a four-seam fastball that’s 1.5 mph faster than it was in 2020 and complemented by an excellent change-up and slider. “We’re seeing him kind of grow up right in front of our eyes,” Mattingly said.

Rogers is occupying the space of “young phenom” that Miami expected Sixto Sánchez to hold prior to the season, but shoulder inflammation and COVID-19 protocols have delayed the start of Sánchez’s season.

One 2020 standout who is living up to the rookie hype is Atlanta Braves hurler Ian Anderson, the only other pitcher this season to accumulate at least 1 WAR already. His 3.27 ERA in 33 innings reflects an arsenal of pitches that is every bit as good as they looked during Atlanta’s 2020 postseason run. Commanding his change-up is a relatively new development, but he’s making up for lost time: He’s got a whiff rate of 42.7 percent on that pitch this season

In the American League, the best rookie pitcher so far has been a reliever. Emmanuel Clase, pitching in the same bullpen as strikeout machine James Karinchak, has earned the lion’s share of the closing duties anyhow, with six saves and 12 games finished after Monday night’s action. His ERA so far is 0.00, which would be an all-time record if he managed it over a full season. But even the peripherals suggest this is real, with a souped-up Mariano Rivera-style repertoire — a cutter, yes, but he throws it at an average of 100.1 MPH — leading to plenty of strikeouts and weak contact.

“I love the way he attacks,” said his manager, Terry Francona. “I think I made a comment in spring training that he may have thrown too many strikes. And if that’s a problem, we can deal with that.”

It turns out, that is not a problem.

Other notable early rookie pitchers include Ryan Weathers, who has a 0.55 ERA in 16⅓ innings for San Diego, primarily as a spot starter; everybody’s Rule 5 favorite Garrett Whitlock, with a 0.63 ERA and 19 strikeouts against two walks in his first 14⅓ innings with the Red Sox; and Michael Kopech of the White Sox, whose 30-4 K-BB ratio over a mix of starts and relief gigs has produced a 1.45 ERA so far. His manager, Tony La Russa, even threw an Adam Wainwright comp on him.

“I don’t have a crystal ball, but if he pitched — and I use the [Adam] Wainwright experience from ’06 — he can pitch in the bullpen all year long and maybe next year win 20 [games], or maybe later on he pitches this year as a starter,” La Russa said last month.

Of course, if that comparison holds, Kopech would pitch only 75 innings. But the White Sox would be World Series champions.

Check out our latest MLB predictions.