The 2018 season's top rookies were announced on Monday, and both Rookies of the Year were mentioned in last year's ROY radar story.
Predicting who will win Rookie of the Year honors a year in advance is tough. Evidence comes from last year's group of 10 candidates. None of the five American League names received a vote (though Gleyber Torres, who finished third in the AL, was on the "others to watch" list). The National League choices were a bit more spot on, with Walker Buehler finishing third and Jack Flaherty landing in fifth place this year.
That's not serving as a deterrent to trying again. All candidates on the lists below are on MLB Pipeline's current Top 100 list.
American League
Vladimir Guerrero Jr., 3B, Blue Jays' No. 1 prospect
The No. 1 prospect in baseball has to be considered the front-runner for ROY honors next year, doesn't he? Guerrero flirted with a .400 batting average for much of the season and reached Triple-A at age 19, finishing the year with an OPS over 1.000 across four levels. He then capped things off with a very productive Arizona Fall League campaign.
Josh James, RHP, Astros' No. 4 prospect
James took as big a step forward in 2018 as any pitching prospect in baseball, with improved conditioning among the factors that allowed him to pitch his way from Double-A to the big leagues. He struck out 13.5 per nine across two Minor League levels, then pitched well enough in Houston to earn a spot on the postseason roster. A full-time spot in the rotation could be his for the taking.
Danny Jansen, C, Blue Jays' No. 3 prospect
A solid all-around backstop, Jansen was able to shake off past injuries to homer in the Futures Game and make his big league debut in 2018. Russell Martin is still under contract for a year, but Jansen should get most of the time behind the plate in '19.
Eloy Jimenez, OF, White Sox No. 1 prospect
If Guerrero Jr. is the front-runner, then Jimenez isn't that far behind. Splitting the year between Double- and Triple-A, the 21-year-old outfielder hit a combined .337 with a .961 OPS. There's no question he'd be an upgrade in one of the outfield corners in Chicago next season.
Kyle Tucker, OF, Astros' No. 1 prospect
Tucker's brief stints in the big leagues in 2018 should not be used to extrapolate any kind of projection. He'll be just 22 for all of 2019 and flat-out raked as one of the youngest players in the Triple-A Pacific Coast League last season. It might be crowded in that Houston outfield, but Tucker and his back-to-back 20-homers/20-steals seasons have the chance to provide a greater everyday impact.
Others to watch:Yordan Alvarez, OF/1B, Astros; Bo Bichette, SS, Blue Jays; Griffin Canning, RHP, Angels; Dylan Cease, RHP, White Sox; Michael Chavis, 3B, Red Sox; Jonathan Loaisiga, RHP, Yankees; Sean Murphy, C, A's; Jesus Luzardo, LHP, A's; Justus Sheffield, LHP, Yankees; Forrest Whitley, RHP, Astros

National League
Peter Alonso, 1B, Mets' No. 2 prospect
Mets fans wanted him up in 2018. After Alonso tied for the Minor League lead in home runs (36) and ran away with the RBI title (119), there's no question his power right-handed bat is ready for Citi Field. Hitting five more balls out in the AFL certainly doesn't hurt, and the Mets have said they're open to having him start the year in the big leagues.
Keston Hiura, 2B, Brewers' No. 1 prospect
Yes, Hiura only has one-plus year of pro ball under his belt, but his bat is so advanced, it's hard to see him needing much more time to be ready. His AFL season (.333/.387/.548 and a league-leading 30 RBIs in 20 games) should be a good springboard for him, providing space has been made in Milwaukee.
Victor Robles, OF, Nationals' No. 1 prospect
Robles was on this list a year ago, but injuries slowed him and Juan Soto passed him by up to Washington. Even though he played just 52 games in the Minors, he did make an impact in the big leagues last year and his tools will definitely play in the Nats' outfield, where he should get the chance to play alongside Soto all year.
Brendan Rodgers, INF, Rockies' No. 1 prospect
The two-time Futures Game participant had a solid season in Double-A to earn a bump to Triple-A before his 22nd birthday. Rodgers' bat speed, power and ability to play three infield positions should help him break into the Rockies' lineup -- and there's no telling what kind of numbers he could put up in Coors Field.
Touki Toussaint, RHP, Braves' No. 4 prospect
There are a number of young Braves pitchers who could figure into ROY talk in 2019. Toussaint gets the nod because of his pure swing-and-miss stuff, the impression he made during his big league callup and the fact the Braves trusted him enough to put him on the postseason roster.
Others to watch:Kolby Allard, LHP, Braves; Logan Allen, LHP, Padres; Luiz Gohara, LHP, Braves; Ke'Bryan Hayes, 3B, Pirates; Dakota Hudson, RHP, Cardinals; Mitch Keller, RHP, Pirates; Francisco Mejia, C/OF, Padres; Austin Riley, 3B, Braves; Keibert Ruiz, C, Dodgers; Nick Senzel, INF, Reds; Mike Soroka, RHP, Braves; Fernando Tatis Jr., SS, Padres; Luis Urias, 2B, Padres; Alex Verdugo, OF, Dodgers; Taylor Widener, RHP, D-backs; Bryse Wilson, RHP, Braves; Kyle Wright, RHP, Braves