10 rookies off to the best starts so far

It's nearly a month since the 2024 season opened in South Korea, so it's time to take a look at the campaign's early top rookie performers, also known as the April edition of MLB Pipeline's Rookie Hot List.

Each month, MLB.com will look at which rookies performed best over the past 30 days. This isn't a prediction of which players will take home Rookie of the Year honors -- it's merely a reflection of how the top prospects have played during this period of time.

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Many exciting debuts have already highlighted this young campaign, but the trio of Jackson Holliday (MLB No. 1), Jackson Chourio (MLB No. 2) and Wyatt Langford (MLB No. 6) didn't crack the 10 performers in April list. We expect these phenoms to make appearances later in the season, but there have been plenty of worthy candidates in the meantime.

Just missing this list is the highest-paid rookie: Yoshinobu Yamamoto. The Dodgers righty has posted an impressive ratio of 21 strikeouts to four walks in four starts but has yet to pitch into the sixth inning and has a 4.50 ERA. Relievers Hunter Gaddis, Cade Smith, Victor Vodnik and Jordan Leasure merit mention for 0.00 ERAs but fell short due to a lack of innings and strikeouts.

But without further ado, let's get to the hottest rookies to start the season (all stats through Monday):

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1. Colton Cowser, OF, Orioles: Cowser has increasingly picked up playing time and really turned it on in the past week. He launched four homers in as many days, and he collected six hits and 10 RBIs in a series at Boston. That's given him a .395/.429/.868 slash line and a .539 wOBA, highest in baseball (min. 40 PA). His defense has been excellent as well, registering 2 Outs Above Average between all three outfield spots.

2. Shota Imanaga, LHP, Cubs: The North Siders' $53 million man couldn't be off to a much better start. Through three outings, the southpaw has yet to give up an earned run while racking up 16 strikeouts and just two walks. Imanaga has been able to get opponents to chase at a stellar 33.0 percent rate, including 53.8 percent of the time on his devastating splitter.

3. Michael Busch, 1B, Cubs: After homering in five straight games, Busch leads all rookies in roundtrippers (six) and stands second in hits (17), RBIs (12) and walks (eight). He has at least one knock in all nine starts, which helped him amass a 1.141 OPS, fourth among qualified hitters. The advanced metrics back up his breakout too, as he ranks in the 99th percentile in barrel rate (21.6 percent) and 93rd percentile in average exit velocity (93.5 mph).

4. Jackson Merrill, OF, Padres: The fact that Merrill has shown off plus defense in center field despite not playing there professionally before this season is incredible. That he's also slashing .356/.433/.441, even in one of the league's most notorious pitchers' parks? Phenomenal. But doing that all as the Majors' third-youngest player, still shy of his 21st birthday, makes it all the more impressive.

5. Evan Carter, OF, Rangers: Carter was a key cog of the Rangers' World Series run down the stretch last season, and he's picked up right where he left off. The 21-year-old has a 132 wRC+ with more walks (10) than strikeouts (nine). One sneaky way he's created value? Using his 97th percentile sprint speed (29.6 ft/sec) to advance safely all 11 times he's tried to take an extra base.

6. Mason Miller, RHP, Athletics: The 25-year-old fireballer has taken well to the closer's role with a 2.25 ERA, 15 strikeouts and three saves in eight innings. After all, no one in the Majors throws harder than Miller, who pumps his fastball in the zone at an average of 100.6 mph. That helps intimidate batters, but his slider has actually been his most devastating pitch, with opponents going just 1-for-15 with a single and eight K's against the offering.

7. Max Meyer, RHP, Marlins: The third overall pick from 2020 has returned from Tommy John surgery looking as good as ever: Meyer has given up just four runs across 17 innings in three starts. Yes, he only has 14 strikeouts during that span, but the K's are coming. He ranks fourth among 134 qualified pitchers with a 36.9 percent whiff rate. The Marlins optioned Meyer to Triple-A Jacksonville on Monday to make room for now-healthy Edward Cabrera and continue to monitor the righty's workload coming off surgery, but it won't be a surprise to see him back in the Majors before long.

8. Masyn Winn, SS, Cardinals: Winn has started 13 games and collected multiple hits in seven of them, helping him post a .370/.388/.500 slash line. It's a small sample size, but he's striking the ball with more authority than he did in his cup of coffee last year (average exit velocity up from 86.0 mph to 90.1). Not to mention that he has the second-best arm strength among shortstops (92.4 mph).

9. Joey Ortiz, 3B, Brewers: Ortiz's .324/.410/.412 slash line is impressive enough as he adjusts to the hot corner full-time, but he's really excelled in the plate discipline department. The 25-year-old ranks in the top quintile in chase rate (20.7 percent, 83rd percentile), whiff rate (13.4 percent, 95th) strikeout rate (15.4 percent, 80th) and walk rate (12.8 percent, 80th).

10. Jared Jones, RHP, Pirates: Don't look too much at his 4.00 ERA: Jones has been one of the most dominant pitchers in the league. Thanks to elite extension and velocity, he paces all rookies with 25 strikeouts and all qualified pitchers with a 39.5 percent whiff rate. With just two walks, he ranks second in baseball in K/BB rate (31.9 percent). Jones' lone blemishes have been the four homers he's allowed, although his minuscule 0.94 WHIP has limited the damage.