Edwin Diaz rebounded yesterday after blowing the save on Sunday with a perfect frame. What was notable was the Fastball usage, as Diaz used his Slider almost exclusively on Sunday and got beat on a hanging Slider by Randy Arozarena.
On Monday, Diaz mixed in his Fastball more and got some swing and misses on that pitch as well. Yes, the velo is down, but the overall numbers for the Fastball are still there.
Diaz overall numbers aren’t 2022 like, but to me that’s a lot to expect on its own, let alone after missing a full season in 2023.
In 2022 Diaz had a 1.31 ERA with 118 strikeouts in 62 innings. It was a historic season, which is hard to duplicate. So far this season Diaz is pitching to a 2.45 ERA over 14.2 innings, striking out 22. Right now his WHIP (0.82) is lower than in 2022 (0.84), showing hitters still having a difficulty getting on base against Diaz.
But yes, the velo is down. Can’t deny that. Diaz average Fastball velo stands at 96.9, more then 2mph lower then his 99.1 average mph in 2022. Still, Diaz should trust his Fastball like he did in Monday’s outing. But, he doesn’t need to over do that too. In 2022, Diaz threw his Slider more then his Fastball, as he threw 58.1% Slider. To put it in perspective, this year he has thrown the Slider 59.6%.
However, Sunday it was to much. The balance on the usage was off. He threw the Slider 79% of the time and the Fastball 11% (2 pitches where unknown by Baseball Savant). Yesterday it was 55% Fastball and 45% Slider. A clear difference in his repertoire. His Fastball is good enough that it works.
Diaz is still at the top of the league in a lot of categories. His expected ERA stand at 1.80, which is 9th in Baseball. He is third on the team behind Ottavino (1.34) and Garrett (1.66), but 9th is still very good. Just shows how good the Mets bullpen is.
He is also at the top of the league on Expected Batting Average, Average exit velo and Whiff and K rate. Yes, Diaz is still an elite arm, even if you consider the lower Velo on his Pitches and lower K rate.
And it shows in Diaz his results. Against the Fastball hitters slash just .154/.269/.385, which is a slightly better OPS against than his Slider, which gets a .171/.301/.371 slash line against. Only major concern right now, the Whiff rate. He is down to 30.6 percent which is more then 10 percent less. However, on Monday Diaz got 3 Whiffs on 4 Swings on the Fastball, which is a good sign.
Diaz will have some rust in his first year after missing 2023, but overall the numbers are still really good. I have no concern about Diaz, keeping his status as an elite reliever up.
