This article is part of our Farm Futures series.
I hope those of you who play in shallow keeper and dynasty leagues enjoyed last week's piece, because this one is for the deep-league crowd. High-caliber breakout players like Daulton Varsho, Jeisson Rosario, Colton Welker, Lucius Fox, Isaac Paredes, Josh Lowe, and Peter Alonso should have been owned in all serious dynasty leagues entering the season, but there are plenty of interesting hitters experiencing a breakout of sorts who are still available in many competitive leagues.
I have combed through each of the 10 full-season leagues to provide one breakout hitter per league. These prospects vary in quality, but I have specifically tried to pick players whose breakouts have the potential to be legitimate, ignoring the low-pedigree hitters who are simply benefiting from a sky-high BABIP through four weeks.
PACIFIC COAST LEAGUE
Oscar Mercado, OF, Cardinals: The worst thing that can be said about Mercado is that he is firmly blocked at the big-league level in 2018. St. Louis has three veteran everyday outfielders and two big-league ready outfield prospects in Tyler O'Neill and Harrison Bader, so a lot would have to go wrong for Mercado to get a long look this season. However, he has some abilities that may allow him to separate himself from the back half of that group in the coming years.
The Cardinals have been trying to inject more speed into the lineup for a few years now, and while Tommy Pham helps in that regard,