Each year, many fantasy owners take chances on rookies and prospects during the later rounds of the draft, with the hopes of these players breaking spring training with the team or being called up during the month of April or May. The task itself can be tricky and even frustrating, but if you can hit on a few players (Ronald Acuna Jr., Juan Soto, etc) - you can really steal some value for later in the season. Here are a few players to keep in mind entering draft day. Some will likely be in the big leagues to start the season, while others will have their service time manipulated in the minor leagues to start the season.
Vladimir Guerrero Jr., 3B, Toronto Blue Jays
Much like Ronald Acuna Jr. last year, Vlad Jr. is more than capable to make the big-league team out of camp, but will likely held back to manipulate his service time. Regardless of when he finally arrives in Toronto, he's a must draft talent even when starting the season at Triple-A. He's the number one prospect in baseball who has 25-30 home run power at the MLB level.
Peter Alonso, 1B, New York Mets
After slugging 36 home runs across two levels last season, Alonso showed his big power bat to the Mets. The 24-year-old is likely blocked at first base right now by Todd Frazier, so he will more than likely open the season at Triple-A Syracuse. Due to injuries and underperforming players, Alonso could be a mid-season callup.
Yusei Kikuchi, SP, Seattle Mariners
Not much is known about Kikuchi with the exception of his Japanese stats, but I think this article from Jeff Sullivan over at FanGraphs sums up what to expect from the 27-year-old lefty:
"He’s not altogether too different from Kenta Maeda and Miles Mikolas, who’ve succeeded after transitioning from Japan. Unlike Maeda and Mikolas, Kikuchi is a southpaw, and he’ll turn 28 in the middle of June. With his low-90s fastball, reliable slider, and slow curve, he pitches in a style similar to Patrick Corbin."
Generally speaking, I'm skeptical of taking a leap on players transitioning from Japan to USA due to the different environments (hitters, workload, etc) - so at best, the lefty starter is a late-round pick, especially for a team like the Seattle Mariners, who are beginning a rebuild in 2019.
Victor Robles, OF, Washington Nationals
Robles has better tools than Billy Hamilton, but like Hamilton, Robles main appeal to fantasy owners is stolen bases. As of right now, Robles figures to be the every day center fielder with Bryce Harper still un-signed, but if Harper does end up re-signing with the Nationals, Robles could split playing time with Adam Eaton. Robles and his stolen bases are a late-round pick.
Garrett Hampson, 2B, Colorado Rockies
Although Daniel Murphy signed with the Rockies during the off-season, his primary position will be first base, leaving the door open for Hampson to take the starting second base position and run with it. In 24 games last season, Hampson hit .275/.396/.400 with zero home runs. Power isn't his game, but getting on base is, as he limits his strikeouts and makes contact. Hampson will be a nice addition as a middle-infielder role, especially with the high scoring Rockies offense.
Eloy Jimenez, OF, Chicago White Sox
Much like Vlad Jr. this year, and Acuna Jr. last year, one of the top prospects may be held down in the minor leagues to start the season. The 22-year-old outfielder flat out hit last season, hitting .337/.384/577 with 22 home runs across two levels of play. He's confident and has his eyes on big expectations for himself. Jimenez was questionable for a call-up last season, but it never happened, likely due to the fact that the White Sox didn't have a need for his services. However, this season, it's just a matter of time before he finds himself playing at the big-league level.