It's the season for fantasy baseball rankings, and this one is for players who are rookie/prospect eligible, which has both a service time and playing time component. Some already have major league experience, but all are still considered Rookie of the Year eligible. I'm ranking them for 2021-only value, so not for their dynasty or keeper league value, and based on a head-to-head category scoring, but will mention players with standout skills for points leagues (like hitters' strikeout-to-walk ratio) as relevant. When referencing average around contact (batting average), power (homers) and plate discipline (strikeout-to-walk ratio), average is a .250 batting average and 15-18 homers in a 550 plate appearances, and 9% walks with 23% strikeout rate for hitters, while for pitchers the important averages are a 4.45 ERA and 9.0 K/9.
Almost every pitcher mentioned here is a starter, and those pitcher averages include relievers, so the standard for an average, or No. 4 starter, is actually lower than that, particularly in strikeout rate. There's a balance between impact/ability and opportunity/playing time which will be noted in the blurb, but the top dozen or so players will be Opening Day starters who will have to be seriously injured or really underperform to lose their spots. And if you have strong preferences for a particular type of prospect, moving one up/down a few spots is fair, as these rankings are pretty tightly packed from top to bottom.
1. Randy Arozarena, OF, Rays
Arozarena has the unique combination of every-day tools, a clear spot in the lineup, not enough experience to have graduated prospect status, but a historic run of performance down the stretch in 2020. I don't think he's a runaway No. 1, since there isn't infield eligibility and he won't be truly elite in any category, but should be above average in every category, unless your league uses hitter strikeout rate.