When the Mets acquired Edwin Díaz in a trade between the 2018 and 2019 seasons, they had gotten control of one of the very best relievers in the game over the preceding three years. Whether or not you agreed with the trade at the time, it was hard to argue that Díaz wasn’t very good.
Having made his major league debut in 2016, Díaz racked up 191.0 innings over the course of three years with the Mariners with a 2.64 ERA and 2.56 FIP, the latter of which combined with his workload to give him 6.3 fWAR, the second-highest mark in all of baseball behind only Kenley Jansen. His 38.8 percent strikeout rate was the sixth-best among qualified relievers. Díaz’s ERA ranked 21st, and the Mets undoubtedly found Díaz’s 2018 season particularly enticing. That year, he threw 73.1 innings with a 1.96 ERA and 1.61 FIP, notching 57 saves along the way. While relievers tend to be more volatile than your average player, it was a breakout year—from a player who was already good.
Since the trade, though, Díaz has been one of baseball’s worst relievers. Of the 179 qualified relief pitchers in Major League Baseball since the start of the 2019 season, Díaz has a 5.55 ERA that ranks 167th. His 4.59 FIP in that time isn’t good, either, even if it suggests that he might be getting worse results than his pitching has deserved.
Some parts of Díaz’s game haven’t changed since the trade. He’s still striking out batters at an incredibly high rate, and he’s still averaging 97.8 miles per hour on his fastball, per Brooks Baseball, and 89.9 miles per hour on his slider. But he’s given up 2.40 home runs per nine innings with the Mets, a drastic jump in that rate when compared to his work in Seattle, and opposing hitters have a .371 batting average on balls in play, a number that can’t just be explained by the Mets’ defensive weaknesses.
In his first appearance this year, Díaz secured a save in the Mets’ Opening Day victory in a 13-pitch inning against the Braves. The next night, he looked good for two outs, and even as he blew the save, he had thrown a pretty good pitch to Marcell Ozuna, who turned it into a solo home run anyway. Perhaps the baseball that was used by Major League Baseball in 2019 and appears to very much still be in use this year is to blame for the spike in Díaz’s home run rate, which has affected some pitchers more than others.
Whatever the case is with home runs, though, Díaz looked downright terrible last night. He threw 35 pitches, recorded just one out, issued two walks, and was only charged with one run because Paul Sewald took over for him—with the bases loaded and that run already in—and got two outs with allowing any of the inherited runners to score.
The nature of the 60-game 2020 season is particularly bizarre since the league is going with vastly-expanded playoffs that will see eight teams from each league in the postseason for the first time in league history. That makes every regular season game less important by definition, but the Mets can’t waste opportunities to pick up wins, either, in a season where seven games constitute 11.67 percent of the entire season.
With several other pitchers who have experience in high-leverage situations in their bullpen—Dellin Betances, Seth Lugo, Justin Wilson, and Jeurys Familia—the team has to get Díaz out of those spots immediately. The Mets’ bullpen lacks depth, but to the greatest extent possible, it has to find him work in spots that have some breathing room. There’s no guarantee that those four pitchers will all be better than Díaz, but the status quo isn’t sustainable. If Díaz finds his dominant self in lower-leverage situations, the team can work him back into increasingly important spots, but he really has to establish that he’s capable of performing at that level before the Mets can trust him again.