By Dan Harris (FantasyPros), Wednesday, May 27th
Diaz's season was an unmitigated disaster. While his strikeout rate remained strong, his ERA ballooned to 5.59, his home run rate rose to comical levels, and his control waned. By the end of the season, he had ceded save opportunities to Seth Lugo and was relegated to mopup duty. Diaz's slider went from being unhittable in 2018 (.129 BAA) to getting crushed in 2019 (.297 BAA). He'll enter 2020 as the closer for the Mets, and reliever volatility is well-known, so don't be surprised to see Diaz rebound big-time in 2020. But just don't go into your season banking on it.