Castillo was added to Miami's 40-man roster Friday, Joe Frisaro of MLB.com reports.

EDGE Analysis

This was a no-brainer for the Marlins, as Castillo still sits toward the top of their prospect rankings following strong showings as a starter for both High-A Jupiter and Double-A Jackson. The 23-year-old routinely touches triple-digits, so even though he's currently progressing as a starter, he could make an impact in the big leagues as a late-inning reliever already in 2017.